Water filter cartridge and manifold head seal

ABSTRACT

A water filter cartridge has a cap with radially oriented first and second (either inlet or outlet) flow channels on first and second generally cylindrical portions. First and second seals encircle the first flow channel on the first portion and third and fourth seals encircle the second flow channel on the second portion. The second and third seals form a void volume during use which may be accessed by a vent path to eliminate moisture or to test for or indicate leaks. The radial flow paths reduce axial, push out forces on the filter cartridge and allow smaller locking tabs to be used. The first seal forms a top void volume during use which may be accessed by a vent path to eliminate moisture or to test for or indicate leaks.

CROSS-REFERENCE TO RELATED APPLICATIONS

The application claims the benefit under 35 U.S.C. §119(e) toProvisional Patent Application No. 61/983,392 filed Apr. 23, 2014 andProvisional Patent Application No. 62/020,218 filed Jul. 2, 2014 theentire contents of which are incorporated herein by reference.

BACKGROUND

The present invention relates generally to water filter cartridges usedin home and business water filter systems, and optionally used incommercial applications. Current filter systems have a manifold headwith a manifold head inlet port connected to a source of water and amanifold head outlet port connected to a dispenser for the filteredwater, such as a household refrigerator, or an apparatus using filteredwater such as a coffee maker. The manifold head typically has agenerally cylindrical, cup shaped interior, and often has a single,uniform diameter or two different diameters forming a steppedconfiguration. A removable filter cartridge has a cartridge head that istypically inserted axially into the manifold head so that lugs orbayonet flanges on the cartridge head or cartridge housing pass throughcorresponding slots in the manifold head. The cartridge is then rotatedso the lugs or bayonet flanges engage inclined locking surfaces on themanifold head to force the cartridge and cartridge head axially towardthe manifold head so as to engage fluid seals located between themanifold head and the cartridge head and to align the manifold headinlet port with a cartridge head inlet and to align a cartridge headoutlet with the manifold head outlet port so water can flow through afilter within the cartridge. The cartridge head is rotated the oppositedirection to remove the cartridge after the filter is exhausted and toallow a fresh filter cartridge to be inserted into the manifold head.

Two or three O-ring seals are used between the manifold head and thecartridge head to separate the inlet and outlet flow paths to and fromthe filter cartridge. One of the seals allows water to flow between theinterior end of the manifold head and the adjacent end of the cartridgehead in a plane orthogonal to the longitudinal axis of the filtercartridge, or the seals allow water to flow between an annular surfaceon the manifold head and an adjacent annular surface on the cartridgehead, which annular surfaces encircle the longitudinal axis of thefilter cartridge. The water pressure on these adjacent and opposingmanifold head and cartridge surfaces that are orthogonal to or inclinedrelative to the longitudinal axis of the filter cartridge exert an axialforce on the cartridge that is proportional to the surface area andwater pressure. This axial force urges the cartridge out of the manifoldhead and is resisted by the cartridge lugs engaging the locking surfaceson the manifold head.

The lugs on the cartridge head or cartridge and the mating lockingsurfaces on the manifold head are substantial in order to maintain thecartridge firmly engaged with the manifold head. The line pressure of amunicipal water source is typically about 40-60 psi and the manifoldhead and/or cartridge head is constructed so that the water exerts anaxial pressure that pushes the cartridge head and cartridge away fromthe manifold head. The larger the diameter of the filter cartridge andcartridge head, the larger the axial force pushing the filter cartridgeaway from the manifold head and the larger the axial force that must berestrained by the lugs and locking surfaces. Since the filter cartridgesare disposable the cartridge heads are of molded plastics, requiring thelugs to be about ¼ to ⅜ inch thick in the axial direction of the filtercartridge in order to secure the cartridges into position in themanifold head with each lug extending about an inch or more around acircumference of the cartridge's cartridge head, and with the manifoldhead locking surfaces having a similar thickness and circumferentiallength. These substantial lugs and locking surfaces require extensivemolding and material. There is thus a need for an improved engagementmechanism that reduces the size of the mating lugs and locking surfaces.

The lugs and locking surfaces are thicker in the axial direction toaccommodate the increased forces and since the length of the manifoldhead and cartridge are limited, the result is that the size of andlength of the mating head is larger and the thickness of the lugs islarger in order to accommodate the increased axial force from the linewater pressure tending to push the filter cartridge out of the matinghead. Further, not only must the lugs on the filter cartridge be largerto accommodate the axial force from the line pressure but the matingsurfaces on the head must also be larger to accommodate the force and toaccommodate the larger filter lugs. Basically, the lugs on the filtercartridge and the mating lugs or locking surfaces on the manifold headmust be similar in size in order for them to work together. There isthus a need for cartridge connecting and retaining mechanism that betteraccommodates the line pressure of the water source.

Additionally, the flow rate through the filter cartridges also increasesthe potential axial force tending to eject the filter from the manifoldhead or head. Historically a ¾′ opening was considered large whereascurrent openings about 1″ in diameter may be considered a minimum insome instances and 1½″ and 2″ diameter flow openings in the filtercartridges are becoming more common. With the increased flow rate thepotential axial ejection force increases. There is thus a need for awater filter cartridge connecting and retaining mechanism that does notrequire so much axial length. There is thus a need for a water filtercartridge that better accommodates the increasing flow rates andresulting potential for increased forces tending to eject the filterfrom the manifold head.

The axial force resisted by the lugs ultimately limits the diameter ofusable filters to about five inches diameter. There is thus a need for away to removably connect replaceable filter cartridges to manifold headsthat more efficiently accommodates the force created by the linepressure of the water source.

As the lugs and locking surfaces become longer in the axial andcircumferential directions, it takes more force to rotate the filtercartridge about the longitudinal axis of the cartridge to engage thelugs and locking surfaces in the circumferential direction and to movethe cartridge axially into position within the manifold head. Thisincreased rotational torque presents difficulties for those with weakerarm strength, especially as the cartridge locations may be difficult toaccess. There is thus a need for an improved way to releasably engagethe removable filter cartridge with the manifold head.

As water pressure is initially applied to an inserted cartridge, theO-ring seals between the cartridge and manifold head will move slightlybefore they seat and seal, and that typically allows a small amount ofwater to leak past the seal. Rapid changes in the line pressure cancause similar movement of the seals and slight leakage or weeping ofwater past the seals and into the dead spaces. The pressure spikesbecome more problematic if an O-ring forms part of two different flowpaths so that an unequal pressure is exerted on different O-rings. Theresult is that small amounts of unfiltered water can bypass the filterelement completely and allow unfiltered water into the filtered waterside thereby contaminating the filter. A very low pressure orno-pressure application may also result in O-rings seals that are notseated sufficiently to prevent small amounts of water passing the seals.The result is that Bacteria and other undesirable growths can developand ultimately bypass the seals, passing from the filtered water side tothe non-filtered side, or passing from the non-filtered side to thefiltered side. For many applications this bypass and actual or potentialcontamination is undesirable, but tolerated. For some applications thisbypass and actual or potential contamination is unacceptable, as inpharmaceutical or biological applications where contamination of thefiltered water may cause contamination or quality control problems andin such situations the solid seals may be used, such as adhesives, toavoid even small leaks. There is a need to avoid these small leaks thatoccur with pressure spikes or from no pressure or so low a pressure asto adequately seat the seals.

Additionally, current contamination testing techniques allow theidentification of chemical contamination down to the parts per trillionlevels. Thus, even very small amounts of water bypassing the O-ring fromthe non-filtered side to the filtered side of the cartridge may show up.While a water filter cartridge may pass a specific contamination testwhen operating in a steady flow condition that same filter cartridge mayfail that same test when water pressures rise and fall dramaticallybetween the inlet and outlet—particularly with membrane or other filtermedia that have high pressure drop across them. There is thus a need foran improved seal between inlet and outlet flow paths of a water filtercartridge.

Once a water filter cartridge is installed, users assume the cartridgewill not leak. Unfortunately, sometimes the cartridge is installedimproperly or for other reasons does not seal properly internally duringmanufacturing and the cartridge does leak and/or the filter media isbypassed. If the leak is readily identifiable it may be checked at thetime of installation. Unfortunately, most filter cartridges do not alloweasy inspection to see if the cartridge is leaking. One exception isU.S. Pat. No. 8,216,463, which provides a seal that allows leakinspection. But that leak detection is not suitable for allapplications. There is thus a need for an improved method and apparatusto indicate whether a removable filter cartridge is leaking, and/orbypassing especially at the time of installation when the cartridge maybe readily examined, reinstalled or replaced if needed.

BRIEF SUMMARY

A manifold head has a barrel valve into which is inserted a filter capconfigured to be placed on the end of a filter cartridge having ahousing with a filter element and internal passages configured to conveyunfiltered fluid from an inlet passage through the manifold head andfilter cap and through the filter element and provide filtered fluid tofilter cap at an outlet in fluid communication with an outlet passagethrough the barrel valve and manifold head. The manifold head, barrelvalve and filter cap have a common longitudinal axis preferablyextending along a length of the cartridge. The engagement between themanifold head and the filter cap is configured so that the inlet andoutlet flow paths through the manifold head, barrel valve and filter capare in a radial plane. The filter cap is removably inserted into thebarrel valve and during filtering use the fluid path between the barrelvalve and the filter cap are further contained in a generallycylindrical, annular space that encircles the longitudinal axis of thefilter cartridge with a different seal on each end of each annularspace. Thus a first flow path in a first radial plane into or out of thefilter cap is defined by first and second seals of a first diameter thatencircle the longitudinal axis and a second radial flow path in a secondradial plane is defined by third and fourth seals of a second diameterthat encircle the longitudinal axis. The first and second flow paths areoffset axially along the length of the longitudinal axis. The first andsecond seals have a first diameter and the third and fourth seals have asecond diameter, and the first and second diameters may be the same ordifferent. The first flow path may form an inlet or outlet with thesecond flow path forming an outlet or inlet, respectively. The seals areretained in grooves and are preferably O-ring seals. The resulting sealconfiguration may avoid creating an axial force that pushes thecartridge away from the manifold head.

Alternatively described, a first flow path oriented in a firstorthogonal plane to the longitudinal axis is located between the firstand second seals placed on opposing ends of that first plane, with thefirst and second seals having the same first diameter. A second fluidflow path oriented in a second orthogonal plane to the longitudinal axisis located between the third and fourth seals on opposing sides of thatsecond plane, with the third and fourth seals having the same seconddiameter. The first and second seal diameters may be the same ordifferent. The first and second seals have opposing and equal axialforces exerted on them, as do the third and fourth seals. But theopposing forces on each pair of seals result in a net zero axial force.The radial flow located between two opposing seals avoids having thewater pressure exert an unbalanced axial force that pushes the cartridgeaway from the manifold head.

The filter cartridge on which the filter cap is placed may be held inplace with retention mechanisms that require little engagement force,with spring detents and removable snap fits believed suitable. Inclinedlugs and locking surfaces may be used to provide a mechanical advantageto engage the seals at the end of the engagement with the manifold head,but the lugs and locking surfaces may be substantially thinner axiallyand shorter circumferentially than previously used for correspondingfilter sizes and water pressures of the prior art. The smaller axialthickness allows a longer filter to be used. The smaller circumferentiallength allows the cartridges to be engaged more easily and allows largediameter cartridges to be manually engaged with the manifold head. Theremoval of the force ejecting the cartridge from the manifold headallows larger diameter cartridges and/or flow ports to be used.

By using two seals encircling the longitudinal axis to define a singleflow path, the pressure force on each seal is approximately the same butin an opposing direction and that helps reduce weeping of small amountsof water past the seals. Further, because the seal arrangement and flowarrangement reduces axial force on the filter and filter nozzle, it ispossible to leak test each filter cartridge before use. A filtercartridge may be inserted into a test manifold head and pressurized gas,such as air, may be introduced instead of water. The leak rate of gasmay be monitored by noting pressure loss, or measuring flow rate neededto maintain a desired pressure. Pressure sensors or flow sensors may beused in connection with vent passages extending through the mating partsto the void volumes between the pairs of seals that define the flow pathin order to monitor leakage into the void volumes. After testing iscompleted the gas pressure may be released and another part tested. Theability to quickly pressurize and depressurize a filter cartridge withair or other gas allows fast relatively inexpensive testing. Currentfilters that contain carbon cannot be tested in this fashion because thecarbon will absorb gas under pressure and will then release the gasslowly and that gas absorption and release defeats the use of rapidpressurization to test for leaks. The use of air or other gas avoidsresidual water in the filter cartridge and greatly reduces the risk ofbacterial growth. The use of vent passages to void volumes allows allareas of the seals to be tested before use. Additionally, the sealtesting ability is especially desirable for a filter cartridge havingtwo, spaced apart nozzle seals on the outside of a tubular nozzle wherethe volume formed between the two seals can be vented to a locationoutside the manifold head and filter cap, thus allowing gas testing ofthe sealing effectiveness of the two, spaced apart, nozzle seals. Sincemore than 1% of filter cartridges may be returned because consumersreport the nozzle seals leak usually where the consumer reports poortaste due to bypass of the filter media or that the filter leaks, theability to test the seal capability before shipment is very desirable.The ability to pressure test the entire filter cartridge and its sealsby accessing the various void volumes to check for leaks, allows theentire fluid cartridge to be tested for leaks using gas or liquid, butpreferably using a gas such as air.

Further, by providing vent passages to the void areas, it becomespossible to not only test that the filter cartridge itself is sealed butit becomes possible to test that the internal filter media is sealed toensure that there is no bypass of the internal filter media. It is notpossible to test for this condition in other current filterconfigurations unless destructive testing of the filter is performed.

In more particularity, a filter cartridge is provided for use with afilter apparatus manifold head having a flow inlet and a flow outlet.The filter cartridge has a filter element located in a housing with thefilter element in fluid communication with a filter inlet and filteroutlet so that liquid from the flow inlet passes through the filterinlet and filter and out the fluid outlet. The filter cartridge includesa filter cap having a first generally cylindrical portion with a firstfluid passageway extending radially inward toward a longitudinal axis ofthe filter cartridge and forming one of the inlet or outlet of thefilter cartridge. The filter cap has a second generally cylindricalportion with a second fluid passageway extending radially inward towardthe longitudinal axis and forming the other of the inlet or outlet ofthe filter cartridge. The filter cap may have a closed top at one endwith the first generally cylindrical portion closer to the closed topthan the second generally cylindrical portion. The filter cap may have afirst internal cavity formed in part by first generally cylindricalinner walls in fluid communication with the first fluid passageway andextending along the longitudinal axis. The filter cap may have a secondinternal cavity in fluid communication with the second fluid passagewayand formed in part by second generally cylindrical inner walls extendingalong the longitudinal axis.

The filter cap further includes first and second seal members encirclingthe first generally cylindrical portion on opposing top and bottom sidesof the first fluid passageway, respectively. Third and fourth sealmembers encircle the second generally cylindrical portion on opposingtop and bottom sides of the second fluid passageway, respectively, withthe second and third seal members being separated by a middle distance.A mounting flange is preferably connected to the filter cartridge withthe mounting flange having outwardly extending mounting tabs configuredto releasably connect the filter cartridge to one of an adapter ormanifold head.

In further variations, the filter cartridge described above may have thesecond generally cylindrical portion having a larger diameter than thefirst generally cylindrical portion and the first inner generallycylindrical walls are smaller in diameter than the second generallycylindrical inner walls. Optionally, a first channel may be formed inthe first generally cylindrical portion, with the first channelencircling at least a substantial portion of the first generallycylindrical portion and located between the first and second seals andin fluid communication with the first fluid passageway. The firstchannel may have an outwardly extending connecting flange at an opposingend of the filter cap and the cap may have a second channel formed inthe second generally cylindrical portion, the second channel encirclingat least a substantial portion of the second generally cylindricalportion and located between the first and second seals and in fluidcommunication with the second fluid passageway.

The filter cartridge advantageously has radial flow passages into andout of the cartridge and filter cap so the mounting tabs may be thinnerthan normal, with a thickness of less than about ⅛ inch believedsuitable when they are made of plastic and have a circumferential widthof less than one inch for a cartridge diameter of about 2 to 4 inches.

There is also advantageously provided a method of testing water filtercartridges having a filter cap. The method includes the steps ofpressurizing a void volume between an inlet and outlet of a water filtercap with a test gas. The void volume is located between two adjacent andcoaxial seal members at least one of which defines a portion of a flowpath through the filter cap of a water filter cartridge. Each of theseal members encircles a longitudinal axis of the filter cap. The methodfurther includes providing a liquid tight seal between a portion of thefilter cap and a wall abutting the two seal members to create the voidvolume and checking to see if the test gas leaks past the two adjacentand coaxial seal members.

In further variations, the checking step comprises monitoring thepressure of the void volume or monitoring the flow path. The checkingstep may include monitoring the flow path for the presence of the testgas. Each of the at least two seals preferably defines a portion of aflow path through the filter cartridge. The two seal members may havedifferent diameters and portions of the filter cap having differentdiameters.

The two adjacent and coaxial seal members may include second and thirdseal members and the filter cap may include first and fourth sealmembers with the first seal member located axially above and coaxialwith the second seal member and with the fourth seal member locatedaxially below and coaxial with the third seal member. The first andsecond seal members preferably each encircle a portion of a filter capadjacent a top of that filter cap and further encircle opposing sides ofa first water flow path of the filter. The third and fourth seal membersmay each encircle opposing sides of a second water flow path of thefilter. The first seal member may form a top filter cap void volumebounded on a lower end by the first sealing member which seals againstthe wall which defines a cavity above the first seal member and intowhich cavity a top of the filter cap extends during testing. The secondand third seal members may form a middle filter cap void volume betweenthe filter cap and the wall. The fourth seal member may form a portionof a bottom filter cap void volume located between the bottom of thefilter cap and a portion of the wall. In this variation, the methodfurther comprises the step of pressurizing at least one of the voidvolumes with the test gas and checking to see if the test gas leaks pastthe two seal members defining the at least one void volume beingpressurized.

The checking step may include monitoring the pressure of the void volumebeing pressurized or monitoring the flow rate of the test gas providedto the void volume being pressurized. The first and second seal memberspreferably have a first diameter and the third and fourth seal memberspreferably have a second diameter, with the first diameter being smallerthan the second diameter. The method may further include pressurizing aplurality of the void volumes with the test gas and checking to see ifthe test gas leaks past the two seal members defining the plurality ofvoid volumes being pressurized. The checking step may include monitoringthe pressure of the void volume being pressurized.

There is also advantageously provided an assembly including at least amanifold and barrel valve for a water filter cartridge for an appliancewhere the assembly having a longitudinal axis. The assembly comprises amanifold that includes several parts, the first of which is a manifoldhead having a manifold wall defining a first generally cylindricalmanifold inner surface centered on the longitudinal axis with a firstmanifold fluid passage passing through the manifold wall and openingonto the first manifold inner surface. The manifold head has a secondgenerally cylindrical manifold inner surface centered on thelongitudinal axis with a second manifold fluid passage through themanifold wall and opening onto the second manifold inner surface. Thesecond manifold fluid passage is spaced apart from the first fluidpassage a distance “d” along the longitudinal axis. The manifold alsoincludes a middle manifold vent passage extending through the manifoldwall and opening onto one of the first or second manifold innersurfaces.

The assembly further includes a barrel valve having a barrel valve wallforming a first barrel valve wall portion having a first outer,generally cylindrical barrel valve surface sized to fit inside the firstmanifold inner surface. The barrel valve wall also forms a second barrelvalve wall portion having a second outer, generally cylindrical barrelvalve surface sized to fit inside the second manifold inner surface. Thefirst barrel valve wall portion has a first barrel valve fluid passageextending therethrough. The second barrel valve wall portion has asecond barrel valve fluid passage extending therethrough and spacedapart a distance along the longitudinal axis below the first barrelvalve fluid passage. The first and second barrel valve fluid passageshave a first position in which the first and second barrel valve fluidpassages do not overlap and are not in fluid communication with anyportion of the first and second manifold fluid passages and have asecond position rotated about the longitudinal axis in which the firstand second barrel valve fluid passages are in fluid communication withthe first and second manifold fluid passages. The barrel valve furtherhas a middle barrel valve vent passage extending through barrel valvewall between the first and second barrel valve fluid passages. Themiddle barrel valve vent passage has a first position that does notoverlap with the middle manifold vent passage and has a second positionthat is in fluid communication with the middle manifold vent passage.

The assembly also preferably includes a top barrel valve seal encirclingthe barrel valve and longitudinal axis and interposed between the firstmanifold inner surface and the first barrel valve outer surface andlocated above the first manifold fluid passage and above the firstbarrel valve fluid passage. A first, middle barrel valve seal encirclesthe barrel valve and longitudinal axis and is interposed between thefirst manifold inner surface and the first barrel valve outer surfaceand located below the first manifold fluid passage. A second, firstmiddle barrel valve seal encircles the barrel valve and longitudinalaxis and is interposed between the second manifold inner surface and thesecond barrel valve outer surface and is located below the first middlebarrel valve seal and above the second manifold fluid passage and abovethe second barrel valve fluid passage. The first and second middlebarrel valve seals define a middle barrel valve void volume betweenthose first and second middle barrel valve seals and the surfaces of thebarrel valve and manifold abutting those first and second middle barrelvalve seals. The middle barrel valve vent passage opens onto the middlebarrel valve void volume when the barrel valve is in the at least thefirst position.

The assembly also preferably includes a first lower barrel valve sealencircling the barrel valve and longitudinal axis and interposed betweenthe second manifold inner surface and the second barrel valve outersurface and located below the second manifold fluid passage and belowthe second barrel valve fluid passage. A top fluid passage seal isinterposed between the first manifold inner surface and the first barrelvalve outer surface and encircles the first barrel valve fluid passagewhen the barrel valve is in at least the second position. The assemblyalso preferably includes a bottom fluid passage seal interposed betweenthe first manifold inner surface and the first barrel valve outersurface and encircling the second barrel valve fluid passage when thebarrel valve is in at least the second position.

In further variations, the above described assembly has the diameter ofthe first manifold inner surface being smaller than the diameter of thesecond manifold inner surface and the diameter of the first barrel valveouter portion is smaller than the diameter of the second barrel valveouter portion. Further, the assembly may include a first fluid passageseal interposed between the first manifold inner surface and the firstbarrel valve outer surface and encircling the first barrel valve fluidpassage when the barrel valve is in at least the second position. Theassembly may also optionally include a second fluid passage sealinterposed between the second manifold inner surface and the secondbarrel valve outer surface and encircling the second barrel valve fluidpassage when the barrel valve is in at least the second position. Amiddle vent fluid passage seal may be interposed between one of thefirst and second manifold inner surface and one of the second barrelvalve outer surface and encircling the middle barrel valve vent passagewhen the barrel valve is in at least the second position.

In further variations, the assembly may include a middle fluid passageseal interposed between the one of the first and second manifold innersurfaces and one of the first and second barrel valve outer surfaces andencircling the middle barrel valve vent passage when the barrel valve isin at least the second position. The first and second manifold fluidpassages are preferably in a first plane orthogonal to the longitudinalaxis and the first and second barrel valve fluid passages are in asecond plane orthogonal to the longitudinal axis. The middle manifoldpassage and middle barrel valve vent passage are preferably alignedalong a radial axis when the barrel valve is in the second position.

The assembly may also include a manifold base with a filter openingsized to receive a filter cap of the filter cartridge, the manifold basehaving a lip extending around the filter opening on an upper surface ofthe manifold base with at least one tab opening extending outward fromthe filter opening. The barrel valve is advantageously located betweenthe manifold base and the manifold head which are configured toconstrain the barrel valve so it rotates only about the longitudinalaxis during use of the barrel valve.

The top barrel valve seal advantageously forms a top barrel valve voidvolume between the adjacent portions of the top of the barrel valve andthe inner surface of the manifold that are enclosed by the top barrelvalve seal. The assembly may then further include a top manifold ventpassage extending through the wall of the manifold and in fluidcommunication with the top barrel valve void volume. The assembly maythen also include a top barrel valve vent passage extending through atop of the barrel valve in fluid communication with the top void volume.

Further, this above described assembly may include a second lower barrelvalve seal encircling the second portion of the barrel valve andlongitudinal axis and interposed between the second manifold innersurface and the second barrel valve outer portion and located below thefirst lower barrel valve seal. The first and second lower barrel valveseals may define a lower barrel valve void volume located between thoseseals and the surfaces of the barrel valve and manifold abutting thosefirst and second lower barrel valve seals. A bottom manifold ventpassage may extend through the second manifold portion and be placed influid communication with the lower barrel valve void volume. A bottombarrel valve vent passage may extend through the second portion of thebarrel valve and be placed in fluid communication with the lower barrelvalve void volume.

The first barrel valve portion preferably has a generally cylindrical,first barrel valve inner surface and the second barrel valve portionpreferably has a generally cylindrical, second barrel valve innersurface coaxial with the first barrel valve inner surface and thelongitudinal axis. In this instance the assembly may include a waterfilter cartridge having a filter cap located along the longitudinalaxis, the filter cartridge having a water filter therein. The filter capmay comprise first and second filter cap portions. The first filter capportion may have a first filter cap fluid passage extending therethroughto a first, generally cylindrical, filter cap cavity. The first filtercap portion is configured to fit inside the first barrel valve innersurface and align with the first barrel valve fluid passage during use.The first fluid passage is preferably in a radial plane. The secondfilter cap portion has a second filter cap fluid passage extendingtherethrough to a second, generally cylindrical, filter cap cavity. Thesecond filter cap portion is located below the first filter cap portionand configured to fit inside the second barrel valve inner surface. Thesecond filter cap fluid passage is also preferably in a radial plane.

The filter cap has a first, middle filter cap seal encircling the firstportion of the filter cap and longitudinal axis and interposed betweenthe first portion of the filter cap and the first inner surface of theouter barrel and located above the first filter cap fluid passage. Thefilter cap has a second, middle filter cap seal encircling the filtercap and longitudinal axis and interposed between the filter cap and oneof the first or second barrel valve inner surfaces. The second middlefilter cap seal is located below the first, middle filter cap seal andabove the second filter cap fluid passage. The first and second middlefilter cap seals define a middle filter cap void volume between thoseseals and the surfaces of the filter cap and barrel valve abutting thosefirst and second, middle filter cap seals. The middle filter cap voidvolume is in fluid communication with a middle barrel valve vent passageextending through the barrel valve and a manifold middle vent passageextending through the manifold wall when the barrel valve is in thesecond position. The filter cap also preferably includes a first, lowerfilter cap seal encircling the second portion of the filter cap andlocated below the filter cap second fluid passage.

In further variations, the assembly with the filter cap also preferablyincludes a top filter cap seal encircling the first portion of thefilter cap and located above the top filter cap fluid passage. A bottomfilter cap seal encircles the second portion of the filter cap and islocated below the second filter cap fluid passage. The filter capassembly may have the top filter cap seal forming a top filter cap voidvolume defined by the top filter cap seal and the facing surfaces of thefilter cap and barrel valve abutting the top filter cap seal. A barrelvalve top vent passage may extend through the top portion of the barrelvalve and in fluid communication with the top filter cap void volume.The top barrel valve seal may form a top barrel valve void volumebetween the adjacent portions of the top of the barrel valve and theinner surface of the manifold that are enclosed by the top barrel valveseal. The top barrel valve void volume is in fluid communication withthe barrel valve top vent passage. A top manifold vent passage mayextend through the wall of the manifold and be in fluid communicationwith the top barrel valve void volume.

The assembly with the filter cap may also include a second, lower filtercap seal encircling the second portion of the filter cap and locatedbelow the first, lower filter cap seal and defining a lower filter capvoid volume between the first and second lower filter cap seals and thefacing surfaces of the filter cap barrel valve which abut the first andsecond lower filter cap seals. A second lower barrel valve seal mayencircle the second portion of the barrel valve and longitudinal axisand be interposed between the second manifold inner surface and thesecond barrel valve outer portion and located below the first lowerbarrel valve seal. The first and second lower barrel valve seals definea lower barrel valve void volume located between those seals and thesurfaces of the barrel valve and manifold abutting those first andsecond lower barrel valve seals. A bottom manifold vent passage mayextend through the second manifold portion and be placed in fluidcommunication with the lower barrel valve void volume. A lower, barrelvalve vent passage may extend through the second barrel valve portionand be placed in fluid communication with the lower filter cap voidvolume and the lower barrel void volume when the barrel valve is in thesecond position.

The assembly with the filter cap preferably has the bottom manifold ventpassage and barrel valve vent passage radially aligned when the barrelvalve is in the second position. The first manifold inner surfacepreferably has a diameter smaller than the second manifold inner surfaceand the first portion of the barrel valve has a first inner diameterthat is smaller than an inner diameter of the second portion of thebarrel valve, and the first portion of the filter cap has a diameterthat is smaller than the diameter of the second portion of the filtercap.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the invention will becomemore apparent in light of the following discussion and drawings, inwhich like numbers refer to like parts throughout, and in which:

FIG. 1 is a sectional view of manifold head mated with a barrel valveand filter cap;

FIG. 2 a is a sectional view of the filter cap of FIG. 1 mated with afilter cartridge;

FIG. 2 b is a sectional view of the filter cap of FIG. 2 a with afilter;

FIG. 3 a is a perspective view of a modified barrel valve of FIG. 1 withthe seal members removed;

FIG. 3 b is a perspective view of a modified filter cap of FIG. 2 withthe seal members removed;

FIG. 4 is a perspective view of an assembly of three manifold heads ofFIG. 1 with the manifold heads connected in series;

FIG. 5 is a perspective view of an assembly of three manifold heads ofFIG. 1 with the manifold heads connected in parallel

FIG. 6 is a sectional view of a manifold head mated with a barrel valveof FIG. 3 a and the filter cap of FIG. 3 b and a vent tube between theseals encircling the inlet and outlet fittings which vent tube extendsto the barrel valve;

FIG. 7 is a sectional view of a manifold head mated with the barrelvalve of FIG. 3 a and the filter cap of FIG. 3 b, and a vent tubebetween the seals encircling the inlet and outlet fittings which venttube extends to a filter cartridge nozzle, with segments rotated so thevent aligns with first and second fittings;

FIG. 8 is a perspective sectional view of a manifold base with threemanifold heads and partial barrel valves in the heads;

FIG. 9 is a sectional perspective view of a manifold base and filtercap;

FIG. 10 a is a top partial section view of FIG. 9 with the manifold headremoved and showing the barrel valve rotated to a closed, no flowposition;

FIG. 10 b is a top partial section view of FIG. 9 showing the barrelvalve rotated to an open flow position;

FIG. 10 c is a top perspective view of FIG. 10 b with the valve head inan open position and associated piping and with part of a manifold headin tact;

FIG. 11 is sectional view taken along section 11-11 of FIG. 13 a showingthe barrel valve and filter cap rotated to a full open flow position;

FIG. 12 is a sectional view taken along section 12-12 of FIG. 13 bshowing the barrel valve filter cap rotated to a full open flowposition;

FIG. 13 a is a top, partial sectional view of a manifold base with threemanifold heads in an open, flow position and with two manifolds having acover removed to show the locking lugs on those two manifold heads andto show aligned passages on the top manifold head;

FIG. 13 b is a bottom view of the manifold base of FIG. 13 a showing thebottom of the filter cartridges;

FIG. 14 is an embodiment showing a manifold and filter cap but omittingthe barrel valve as also shown in FIG. 7, but further having ventpassages to void volumes between seals;

FIG. 15 is a schematic of a test sequence for testing components ofwater filter fittings;

FIG. 16 is a schematic of a test arrangement for testing components ofwater filter fittings;

FIG. 17 is a schematic of a further test arrangement for testingcomponents of water filter fittings;

FIG. 18 is a schematic of a further test arrangement for testingcomponents of water filter fittings;

FIG. 19 a perspective view of a filter cap with a lateral connectioninstead of an axial connection, with no sealing rings on the filter cap;

FIG. 20 is a sectional view of a filter cartridge and the filter cap ofFIG. 19;

FIG. 21 is a sectional view of the filter cap of FIG. 19;

FIG. 22 is an upper perspective view of several filters and manifoldheads connected in parallel;

FIG. 23 is a partial, upper perspective view of a filter and manifold ofFIG. 22 with a filter removed;

FIG. 24 is a sectional view of the filter cap of FIG. 23 taken alongsection 24-24;

FIG. 25 is a partial sectional view taken along section 25-25 of FIG.24;

FIG. 26 is a partial sectional view taken along section 26-26 of FIG.24; and

FIG. 27 is a sectional view of the manifold of FIG. 23 taken along axis14′.

DETAILED DESCRIPTION

Referring to FIGS. 1-3, 6-7 and 11-12, a filter manifold head 10 isconnected to a manifold base 11. The manifold head 10 has a sidewall 12(FIGS. 11-12) encircling longitudinal axis 14 and connected to end wall16 to close one end of the manifold head and form a hollow interior withan opening opposite end wall 16. The sidewall 12 may have a firstgenerally cylindrical portion 18 adjacent the end wall 16 and having afirst interior diameter MID1 (Manifold Inner Diameter 1). The sidewall12 may have a second portion 20 adjoining the first portion and closerto the open end of the manifold head with the second portion 20 having asecond interior diameter MID2 (Manifold Inner Diameter 2).Advantageously MID2 is greater than MID1 and the end wall 16 isorthogonal to the longitudinal axis 14. Advantageously an outwardlyextending mounting flange 22 encircles at least part of and preferablythe entire open end of the manifold head 10. The mounting flange 22advantageously has a skirt or sidewall or flange 24 depending parallelto axis 14 in a direction away from end wall 16. The sidewall 24 mayhave an internal diameter MID3 (Manifold Inner Diameter 3).Advantageously the diameter MID3 is greater than diameter MID2. Themanifold sidewall 12 and sidewall portions 18, 20, 24 encircle and arecentered along the longitudinal axis 14.

As used herein the relative terms inner and outer, inward and outwardrefer to relative directions toward and away from longitudinal axis 14,respectively or the position relative to that axis. The relative termsup and down, above and below, top and bottom refer to directions alonglongitudinal axis 14 when in the vertical position as shown in FIG. 1 orpositions relative to such axial directions.

A first manifold flow passage 28 extends through the first manifold headsidewall 12 and through a first fitting 30 extending outward from thefirst sidewall. A second manifold flow passage 32 extends through thesecond sidewall portion 20 and through second fitting 34 extendingoutward from the second sidewall portion 20. The fittings 30, 34 arepreferably generally cylindrical tubes sufficiently stiff so thatflexible hose may be forced over the fittings to form fluid connections.The fluid flow passages 28, 32 may be of various cross sectional shape,but are preferably generally cylindrical passages. More preferably theflow passages 28, 32 may have a diameter that increases as the flowpassages extend away from the manifold head through the sidewall andassociated fittings 30, 34. The flow passages 28, 32 are thus preferablyslightly conical in shape, expanding outward away from longitudinal axis14. As shown in FIG. 1, and more readily seen in FIGS. 1 and 6, the flowpassages 28, 32 are tapered along the fitting length while the flowpassage 32 is generally cylindrical and constant along the fittinglength. This slight taper in one flow passage is believed advantageouswhen the tapered flow passage is an outlet flow passage as it may createa slight venturi effect facilitating flow.

Depending on the specific use, the first fitting 30 and its flow passage28 may form a flow inlet in which event the second fitting 34 and itsflow passage 32 form a flow outlet. Conversely, the first fitting 30 andits flow passage 28 may form a flow outlet in which event the secondfitting 34 and its flow passage 32 form a flow inlet. The fittings 30,34 and their associated flow passages 28, 32 are preferably radiallyoriented relative to longitudinal axis 14, but could enter at atangential angle in an orthogonal plane to that axis. Preferably, thefirst and second fittings 30, 34 are on opposing sides of the manifoldhead 10 and thus 180 degrees apart, but they could be at any orientationrelative to each other. In the depicted embodiment the second fitting 34and second flow passage 32 are located below the first fitting and firstflow passage 32, and are adjacent to the mounting flange 22, while incomparison the first fitting 30 and its flow passage 28 are locatedcloser to the end wall 16. The manifold head 10 is preferably molded ofa suitable polymer material compatible with the intended use, such aspolyethylene, polypropylene, ABS, nylon or other suitable plasticcompatible with drinking water, and such molding typically results inthe walls of the manifold head having generally uniform thickness.

A valve body, referred to herein as barrel valve 36 may be configured tofit within the inside of the filter manifold head 10. The barrel valve36 may have a first portion 38 having a generally cylindrical outerdiameter BVOD1 configured to nest closely with the first portion 18 ofmanifold head 10 which has an inner diameter MID1. The outer diameter isgenerally cylindrical but has grooves 42 a in it as described later soit is referred to herein as generally cylindrical or cylindrical andreferences to the cylindrical surface in which such grooves 42 (44, 50,62, 64, 72, 74, 9, 104, 106 etc. as descried later) are located includesthe groove unless otherwise noted as by defining the grooves in thesurface. A clearance between BVOD1 and MID1 of about 0.010-0.015 in(about 2-4 mm) is believed suitable, but the clearance will vary withmanufacturing tolerances, materials and conditions of use, as is thecase with the other clearances discussed herein. The barrel valve 36 mayhave a second portion 40 having a generally cylindrical outer diameterBVOD2 configured to nest closely with the second portion 20 of manifoldhead 10 which has an inner diameter MID2. The second portion 40 isgenerally cylindrical but has grooves 74 a as described later so it isreferred to herein as generally cylindrical. A clearance between BVOD2and MID2 of about 0.010-0.015 in (about 2-4 mm) is believed suitable.BVOD2 is larger than BVOD1. At the bottom of the barrel valve body 36 isan outwardly extending flange 41 used to connect the barrel valve to themanifold base 11, as described later.

The outer surface of barrel valve may have one or more grooves toreceive and hold seals that prevent fluid flow past the seals andbetween the manifold head 10 and barrel valve 36. Advantageously, firstseal groove 42 a is located at the top of the barrel valve 36 in thefirst portion 38 and is configured to hold a seal 42 b. The first sealgroove 42 a is located above the first flow passage 28 and any sealassociated with that flow passage. A second seal groove 44 a is locatedat the bottom of the barrel valve 36 in the second portion 40 and isconfigured to hold a seal 44 b. The groove 44 a is preferably in thesame orthogonal plane as flange 22. The groove 44 a is preferably belowthe second fluid passage 32 and any seal associated therewith. Thegrooves 42 a, 44 a encircle the circumference of the barrel valve 36 andare orthogonal to the longitudinal axis 14 during use. The crosssectional shape of the grooves 42 a, 44 a can vary, as can thecross-sectional shape of the seals 42 b, 44 b. Preferably the grooves 42a, 44 a are rectangular in cross-sectional shape and the seals 42 b, 44b are circular in cross-sectional shape to form O-ring seals 42 b, 44 b.The seals 42 b, 44 b are configured to form a fluid seal between theouter surface of the barrel valve 36 and the abutting surfaces of themanifold head 10. The barrel valve 36 has a top end 46 having a topsurface that is immediately adjacent to the inside surface or lowersurface of end of 16 of the manifold head 10 during use.

A first valve body flow passage 48 extends through the first portion 38of the barrel valve 36 at a location that coincides with the location ofthe manifold head first flow passage 28 when the barrel valve is nestedinside the manifold head. The valve body flow passage 48 is preferablyaligned with the first manifold head flow passage 28, both of which arepreferably radial. The outer surface of the barrel valve 36 has a recess50 a in the face of the barrel valve that encircles the first valve bodyflow passage 48 and a first valve body passage seal 50 b (FIG. 6) fitstherein to encircle the flow passage 48 and to form a fluid seal aroundthe periphery of the juncture of first flow passages 28, 48. The seal 50b is preferably a face seal formed in barrel valve body 36 andcomprising an O-ring seal but ring seals with other cross-sectionalshapes can be used.

A second valve body flow passage 52 extends through the second portion40 of the barrel valve 36 at a location that coincides with the locationof the manifold head second flow passage 32 when the barrel valve isnested inside the manifold head. The valve body flow passage 52 ispreferably aligned with the second manifold head flow passage 32, bothof which are preferably radial. The outer surface of the barrel valve 36has a recess 54 a in the face of the valve 36 that encircles the secondvalve body flow passage 52 and further has a second valve body passageseal 54 b (FIG. 6) that fits therein to encircle the flow passage 52 andto form a fluid seal around the periphery of the juncture of second flowpassages 32, 52. The seal 54 is a face seal formed in the outer surfaceof barrel valve 36 and interposed between the outer surface of thebarrel valve 36 and the inner surface of the manifold head andencircling the juncture of the passages 52 and 32. The seal 54 b ispreferably an O-ring seal but ring seals with other cross-sectionalshapes can be used. The recesses 50 a, 54 a may have a curved bottom toallow the seals 50 b, 54 b to curve with the generally cylindrical outersurface of barrel valve 36 and seal well against the inside generallycylindrical surface of the manifold head 10. The seal 42 b is locatedabove seal 50 b, and seal 44 b is located below seal 54 b so the sealsdo not impede each other's performance. The seals 50 b, 54 b are inplanes orthogonal to longitudinal axis 14 while seals 50 b, 54 b are incurved planes concentric with longitudinal axis 14.

The first portion 38 of barrel valve 36 has a generally cylindricalinner surface having an inner diameter BVID1 (Barrel Valve InnerDiameter 1). The second portion 40 of barrel valve 36 has a generallycylindrical inner surface having an inner diameter BVID2 (Barrel ValveInner Diameter 2). These surfaces are sized to nest with correspondingsurfaces on filter cap 56 that is configured to nest inside and sealagainst barrel valve 36. The filter cap 56 is configured to be connectedto a filter cartridge 55 (FIGS. 2 a-2 b) having a filter housing 57containing a filter element 59 (FIG. 2 b).

Filter cap 56 has a first generally cylindrical outer portion 58configured to fit inside and nest with the inside surface of firstportion 38 of barrel valve 36. Filter cap 56 has a second, generallycylindrical outer portion 60 configured to fit inside and nest with theinside surface of second portion 40 of barrel valve 36. The secondportion 60 is generally cylindrical but has grooves and a channel in itas described later so it is referred to herein as generally cylindricalportion 60. The outer diameter of the first, generally cylindrical,outer portion 58 of filter cap 56 is FCOD1 (Filter Cap Outer Diameter 1)and the outer diameter of the second outer portion 6 of filter cap 56 isFCOD2 (Filter Cap Outer Diameter 2). FCOD 2 is greater than FCOD1. Aclearance between BVID1 and FCOD1 of about 1-5 mm is believed suitable,with the clearance increasing as the diameter of the mating partsincreases. A clearance between BVID2 and FCOD2 of about 1-5 mm isbelieved suitable, with the clearance increasing as the diameter of themating parts increases. The clearance will depend on the fit required bythe seals to achieve a water-tight fit between the mating parts.

The first portion 58 is generally cylindrical but has grooves and achannel in it as described later so it is referred to herein asgenerally cylindrical portion 58. The first portion 58 of the filter cap56 contains a first pair of spaced apart, circumferential grooves, firstand second grooves 62 a, 64 a respectively, containing first and secondseals 62 b, and 64 b, respectively. As used herein the term “seal” maybe used to refer to either the seal member such as seal member 62 b or64 b, or it may refer to the seal member and any accompanying (butoptional) groove 62 a, 64 a. Between the grooves 62 a, 64 a is a firstfilter cap fluid channel 66 also formed in the outer surface of thefirst portion 58 of the filter cap 56. The first fluid channel 66encircles at least a substantial portion (over about 70% of the totalcircumference) of the cap 56 and preferably extends around acircumference of that cap 56 at the location of that first channel. Thefirst filter cap fluid channel 66 may be located in the same orthogonalplane as the first fluid passages 28, 48 and is in fluid communicationwith the first fluid passages 28, 48. The first and second seals 62 b,64 b are on opposing sides of the first filter cap fluid channel 66,above and below that channel to prevent fluid from the first passages28, 48 from leaking axially past the seals 62 b, 64 b. One or morefilter first cap openings 68 extend inward through the walls of thefirst portion 58 of filter cap 56 to place a first internal passage 70of filter cap 56 in fluid communication with the annular channel 66 andfirst fluid passages 48 and 28. The first internal passage 70 is formedat least in part by first inner generally cylindrical walls centered onlongitudinal axis 14 and located to mate with a nozzle of a filtercartridge as described later. The second portion 60 is larger indiameter than the first portion 58 so there is a lateral or radialoffset forming shoulder 69 (FIGS. 3 b and 10) which adjacent manifoldshoulder 29 during use. The lateral offset is optional as the first andsecond portions 58, 60 could be the same diameter, the diameter of thefirst and second portions 38, 40 of the barrel valve and could be thesame, and first and second portions 18, 20 of the manifold head couldeach have the same diameter.

The second portion 60 of the filter cap 56 contains a second pair ofspaced apart, circumferential grooves, third and fourth grooves 72 a, 74a respectively. Third and fourth grooves 72 a, 74 a contain third andfourth seals 72 b, 74 b, respectively. Located between the third andfourth grooves 72 a, 74 a is a second filter cap fluid channel 76 alsoformed in the outer surface of the second portion 60 of the filter cap56. The second filter cap fluid channel 76 encircles at least asubstantial portion (over about 70% of the total circumference) of thecap 56 and preferably extends around a circumference of that filter cap56 at the location of the second channel. The second filter cap fluidchannel 76 may be located in the same orthogonal plane as the secondfluid passages 32, 52 and is in fluid communication with the secondfluid passages 32, 52. The third and fourth seals 72 b, 74 b are onopposing sides of the second filter cap fluid channel 76, above andbelow that channel to prevent fluid from the second passages 32, 52 fromleaking axially past the seals 72 b, 74 b. One or more openings 78extend inward through the walls of the second portion 60 to place asecond internal passage 80 of filter cap 56 in fluid communication withthe second annular channel 76 and second fluid passages 52, 32. Thesecond internal passage 80 may have inner generally cylindrical wallsextending along longitudinal axis 14.

The first and second seals 62 b, 64 b are configured to form a fluidseal between the outer generally cylindrical surface of the filter capat the first portion 58 and the facing generally cylindrical surface ofthe barrel valve 36 so that fluid from the first passages 28, 48 flowsinto the annular channel 66. The third and fourth seals 72 b, 74 b areconfigured to form a fluid seal between the outer generally cylindricalsurface of the filter cap at the second portion 60 and the facinggenerally cylindrical surface of the barrel valve 36 so that fluid fromthe second passages 52, 32 flows into the second annular channel 76.Fluid seals 62 b, 64 b between the first portions 38, 58 of the barrelvalve 36 and filter cap 56 help define a first flow path throughpassages 28, 48, 66, 68 to first internal passage 70. Fluid seals 72 b,74 b between the second portions 40, 60 of the barrel valve 36 andfilter cap 56 help define a second flow path through passages 32, 52,76, 78 to second internal passage 80. When first internal passage 70 isin fluid communication with the inlet of filter element 59, the secondinternal passage 80 is in fluid communication with the outlet of thatfilter element. When the first internal passage 7 is in fluidcommunication with the outlet of filter element 59, the second internalpassage 80 is in fluid communication with the inlet of that filterelement. The particular paths by which water is routed from the first orsecond passages 70, 80 through the filter 59 will vary with theparticular configuration of filter cartridge 55 and is not described indetail herein.

An optional fifth groove 90 a may contain an optional fifth seal member90 b, with the groove 90 a encircling the circumference of the filtercap 56 so as to place the fifth seal member 90 b at a location below thefourth seal member 74 b and fourth channel 74 a, yet at a location thatseals against the barrel valve 36. As depicted in FIG. 1, the bottomedge of the barrel valve 36 is generally cylindrical and the fifthgroove 90 a is formed in that bottom edge of the barrel valve 36. It isbelieved suitable to locate the fifth groove 90 a and outward extendingflange 82 (FIG. 1) at the bottom of the filter cap or with the fifthseal 90 abutting the bottom of the barrel valve 36, or as shown in FIG.7, to locate the fifth seal 90 below the lower seal 74 in the secondportion 60 of the filter cap 56. The fifth seal 90 preferably comprisesa fifth groove 90 a and flexible seal member 90 b to form a radialoriented, sliding seal if located on the sidewall of the second portion60, or form an axial oriented seal if located on the laterally extendingflange 82. It is believed preferable to locate that 90 a groove and sealmember 90 b between the mating surfaces 60 of the barrel valve 36 andsurfaces 40 of the filter cap 56 only if there is sufficient room belowthe fourth seal member 74 b and the bottom end of the barrel valve. Anaxial facing seal located on lateral flange 82 allows a shorter filtercap 46 but is more difficult to form a fluid tight seal because axialpressure is required to compress the seal member 90 b. The radial sealbetween sidewall portions 60, 40 requires no axial force other than toinsert the parts together but it requires a longer filter cap, valvebody and manifold head.

The cross sectional shape of the grooves 62 a, 64 a, 72 a, 74 a, 90 acan vary, as can the cross-sectional shape of the seals 62 b, 64 b, 72b, 74 b and 90 b. Preferably the grooves 62 a, 64 a, 72 a, 74 a and 90 aare rectangular in cross-sectional shape and the seals 62 b, 64 b, 72 b,74 b and 90 b are circular in cross-sectional shape to form O-ring seals62 b, 64 b, 72 b, 74 b and 90 b.

The first through fourth seals 62 b, 64 b, 72 b, 74 b offer a number ofadvantages. The first seal member 62 b prevents fluid from entering thespace between the top 86 of the filter cap and the top 46 of the barrelvalve and that avoids an axial pressure that would tend to push thefilter cap out of or away from the barrel valve 36 and manifold head 10.Moreover, The flow passages 78, 48, 66, 68 are located in substantiallythe same orthogonal or radial plane so that the entry or exit of waterthrough those passages does not exert any axial force to urge the filtercap out of the manifold head and barrel valve. The force frompressurized water is exerted equally in opposing directions on the sealsand surfaces defining the flow passages. The fluid pressure between thefirst and second seals 62 b, 64 b are predominantly reacted within thefilter cap 56 since the upward force on seal member 62 b is reacted bygroove 62 a and is offset by the downward force on seal member 62 b thatis reacted by groove 64 a. Further, the first and second seals are thesame diameter and coaxial so there is no substantial, un-opposed radialor laterally offset surface for the pressure to act upon and create adownward force to urge the filter cap 56 out of the barrel valve andmanifold head. The first fluid passage thus enters or leaves themanifold head 10 in the radial plane to the axis 14 and the first andsecond seals help define that radial volume and the radial parts of thefilter cap, barrel valve and manifold head counteracting the pressureforces from the fluid.

Likewise, the flow passages 32, 52, 70 and 78 are located insubstantially the same orthogonal or radial plane so that the exit orentry of water through those passages does not exert any axial force tourge the filter cap out of the manifold head and barrel valve. Thepressure on the first and second seals 62 b, 64 b are substantially thesame since both seals have the same diameter and are coaxial, seal thesame two parts and form a fluid tight cavity enclosing channel 66. Thisequalized pressure is believed to help the seals seal better and isbelieved to help reduce weeping of moisture past the seals by reducingpressure differentials between these paired seals.

Likewise, the fluid pressure between the second and third seals 72 b, 74b are predominantly reacted within the filter cap 56 since the upwardforce on seal member 72 b is reacted by groove 72 a and is offset by thedownward force on seal member 74 b that is reacted by groove 74 a. Thereis no substantial, unopposed, laterally offset surface for the pressureto act upon in an unopposed manner so to create an axial force urgingthe filter cap out of or away from the manifold head and barrel valve.The pressure forces from the fluid are reacted in predominantly radiallydirections. Likewise, the pressure on the first and second seals 72 b,74 b are substantially the same since both seals have the same diameterseal the same two parts and form a fluid tight cavity enclosing channel76. This equalized pressure helps the seals seal better and is believedto help weeping of moisture past the seals by reducing pressuredifferentials between these paired seals. The second fluid passage thusleaves or enters in the radial plane to the axis 14 and the third andfourth seals help define that radial volume and the radial parts of thefilter cap, barrel valve and manifold head counteracting the pressureforces from the fluid.

The first set of seals 62 b, 64 b are preferably smaller in diameterthan the second set of seals 72 b, 74 b and thus there is a laterallyextending shoulder 69. But pressurized fluid is prevented from exertingan axial force on this shoulder 69 as it is located between the secondand third seals 64 b and 62 b. Likewise, in the depicted design of FIG.1 there is a lateral shoulder 82 at the bottom of the filter cap 56 butfourth seal member 74 b prevents fluid pressure from exerting an axialforce on that laterally or radially extending shoulder.

The radially or laterally oriented first flow paths 28, 48, 66, 68 andthe laterally or radially oriented second flow paths 32, 52, 76, 78provide lateral flow passage means for reducing axial forces thatseparate the filter cap 56 from the valve body 36 or from the manifoldhead 10 or both. The first pair of seals and corresponding grooves 62 a,62 b, 64 a, 64 b having the same first diameter and the second pair ofseal members and corresponding grooves 72 a, 76 b, 74 a, 74 b having thesame second diameter provide first seal means for confining lateral flowpassages to avoid unbalanced axial pressure on axial surfaces of thebarrel valve, filter cap and manifold head as would urge the filter cap56 and cartridge out of the manifold head 10 or barrel valve 36.

By having the flow passages enter in a radial plane that is generallyorthogonal to the longitudinal axis 14, by using the first, second,third and fourth seals 62 b, 64 b, 72 b, 74 b to restrict thepressurized volumes to parts of the filter cap 56 that lack anyappreciable lateral surface on which the pressure could generate axialforces to urge the filter cap away from the barrel valve 36 or manifoldhead 10 and by configuring the filter cap, barrel valve and manifoldhead so they lack the laterally extending areas within those sealedvolumes, the axial force tending to push the filter cartridge 55 out ofthe manifold head 10 or barrel valve 36, is significantly reduced anddesirably eliminated. Because the axial force along axis 14 is sogreatly reduced or eliminated the retaining mechanism used to retain thefilter cap 56 in the barrel valve 36 and manifold head 10 may besignificantly reduced in strength and simplified. If mounting lugs 160on the cartridge or filter cap 56 are used to releasably engage lockingsurfaces 168 on the manifold head 10 to retain the filter cartridge 55in position, then the size and strength of the lugs 160 may besignificantly reduced. The lugs 160 are preferably few in number,advantageously less than about 10, and preferably two, three or fourlugs are used. Lugs having an axial thickness of about 3/32 to ⅛ inchare believed suitable, with a circumferential length of about ¼ to ⅜inch measured at the juncture with the cartridge cap 56 or to the bodyof the filter cartridge 55. Because the axial force from the waterpassing through the filter cartridge 55 is reduced the mounting tabs areconfigured to support the weight of the filter cartridge during use andenvironmental loads, but need not include any appreciable component forthe ejection force from the water, and preferably is sized using lessfrom 5-50% of the force normally attributed to the force from the waterline pressure. Also, because the axial force is reduced by the radialentry and exit of the flow paths through the filter cartridge 55, thediameter of the filter may be increased well beyond five inches.

Referring to FIGS. 1, 2 a, 2 b and 6, the lower end of filter cap 56 hasan outwardly extending flange 82 that forms a shoulder from whichdepends a skirt 84 (FIG. 2 a) configured to connect to the cartridgehousing 57. At the top end of the filter cap 56 is a top end 86 that hasa top surface that is immediately adjacent to the inside surface orlower surface of end 46 of the barrel valve 36. Extending outward fromthe shoulder 82 is one or more, and preferably a plurality of the filtercap mounting lugs 160. The filter cap lugs 160 and slots 25 arecorrespondingly sized and located so the lugs 160 may pass axiallythrough the slots 25 to engage and disengage the filter cap 56 from thebarrel valve 36 and manifold head 10. When the filter cap 56 is advancedinto the manifold head a distance so that the lugs 160 are on the upperside of a lip or locking surfaces 27 of the manifold base 11 which lip27 surrounds the opening through which the filter cap 56 is inserted,then the filter cap 56 and filter cap lugs 160 may be rotated about axis14 to releasably lock the filter cap to the manifold head. One or bothof the edges of filter cap lugs 160 and the entrance to the lip orlocking surface 27 may be inclined so that rotation of the filter capand lugs causes the filter cap to advance further into the barrel valve36 and manifold head 10 to seat the filter cap into an operatingposition. The incline may form cammed surfaces on one or both of thelugs 160 and locking surface 27 to provide a mechanical advantage tohelp overcome any resistance from the seals 62 b, 64 b, 72 b, 74 b and90 b and ensure the filter cap 56 is in the desired axial position. Thetop end 86 of the cartridge cap 56 and the shoulder 69 on the cap 56 caneach serve to limit the distance that the cap 56 is inserted into thebarrel valve 36 and manifold head 10.

FIG. 1 shows the first and second fittings 30, 34 on opposite sides ofthe filter manifold head. If the annular flow channels 66 and 76encircle the filter manifold head and axis 14 the fittings 30, 34 may belocated anywhere around the circumference of the channel. FIG. 1 showsthe fittings 30, 34 on opposite sides of the filter manifold head 10.FIGS. 6 and 12 show the first and second fittings 30, 34 on the sameside of the manifold head 10. The fluid passage fittings 30, 34 and thevent fittings 140, 105, 158 described later are shown in the same planefor ease of description, but may be located at various relativeorientations to make it easier to access the various fittings.

The manifold head 10 of FIG. 6 has the same basic parts as the manifoldhead of FIG. 1 and a detailed description of the parts common to bothFigures is not repeated. The first fitting 30 forms first flow passage28 which is in fluid communication with the first flow passage 48through the barrel valve 36 and first filter cap fluid channel 66 andfirst filter cap openings 68 through the walls of filter cap 56. Thesecond fitting 34 is located below fitting 30 and in the same radialplane. The second fitting 34 forms second flow passage 32 which is influid communication with the second flow passage 52 through the barrelvalve 36 and second filter cap fluid channel 76 and second filter capopenings 78 through the walls of filter cap 56.

While the first ring seal member 62 b prevents fluid from gettingbetween the top end 86 and top end 46, it is possible some fluid mayaccumulate there over time by weeping of the seal, or a faulty seal orassembly may result in a leak of variable size. For some applicationssuch as biological or pharmaceutical uses it is desirable to have thevoid between end 86 and end 46 as dry as possible, or to be able todetermine if there was a leak as reflected by fluid within this space.The same applies to the void volume between second and third seals 64 b,72 b and to the void volume between fourth seal member 74 b and fifthseal member 90 b. An access fluid passage may be formed to connect thesevoid volumes with the outside or exterior of the manifold head 10. Theaccess fluid passage is preferably formed by a series of aligned accessopenings extending at least through the intervening barrel valve 56where fluid leaking into the void volumes would be visible through awindow or viewing port in the manifold head 10. Preferably though,access fluid passage is preferably formed by a series of aligned accessopenings extending through both the intervening barrel valve 56 and themanifold head 10 so that fluid leaking into the void volumes could beconveyed to a location outside the manifold head 10. If the access fluidpassageway to the void volumes is open to atmosphere and large enough toallow evaporation of the fluid then the access fluid passageway may beused as a drying mechanism to reduce the moisture in the void volumessufficiently to inhibit the growth of undesirable organisms beyondacceptable limits. If desired, two access passages could be provided toeach void volume and air, nitrogen or other gas passed through the voidvolumes and access passages to dry the void volumes. Inert nitrogen gascould even be blown over a heating element and passed through the accesspassages and void volumes to ensure dry void volumes if the inert anddrying properties of the gas were warranted for the specificapplication.

Thus, referring to FIG. 6, a middle manifold ventilation passage 100 isformed through the sidewall 12 of the manifold head and is aligned withmiddle barrel valve ventilation passage 102 formed through the sidewallof the first or second portions 38, 40 of the barrel valve 36 and shownin FIG. 6 as extending through the sidewall of the second portion 40 ofthe barrel valve, just below the shoulder radially offsetting the bodyportions. To prevent leaks from the manifold and barrel valveventilation passages 100, 102 between barrel valve 36 and manifold headsidewall 12, seals are placed above and below the vents. Thus, an upperring seal 104 b is placed in groove 104 a encircling the barrel valve 36above the juncture of the vent passages 100, 102. The seal 104 b forms afluid tight seal between the barrel valve and manifold head sidewall. Alower ring seal 106 b is placed in groove 106 a encircling the barrelvalve 36 below the juncture of vent passages 100, 102. An O-ring seal isbelieved suitable for seals 104 b, 106 b. The seals 104 b, 106 b preventmoisture from entering the space between manifold head 10 and the barrelvalve 36 through vent passages 100, 102. The seals 104 b, 106 b are thusinterposed between the manifold head 10 and barrel valve body 36,preferably between the second portion 40 and sidewall 12.

The manifold and middle barrel valve ventilation passages 100, 102 arealigned to vent the middle filter cap void volume located between seals64 b and 72 b and between the filter cap 56 and barrel valve 36. Agenerally cylindrical passage is believed suitable for middle ventpassages 100, 102 and those passages are preferably radially aligned andorthogonal to axis 14. Advantageously the middle vent passage extendsoutward from the manifold head through a middle vent fitting or passage105 to make it easier to apply positive or negative pressure to themiddle void volume, as for example, to blow air or heated gas into themiddle void volume or to apply a (slight) negative pressure. A tubularfitting 105 is shown.

In use, the upper or first fitting 30 forms the inlet port and the loweror second fitting 34 forms the outlet port for a filter cartridge. Themiddle vent passage is preferably a generally cylindrical vent passage100, 102 about ⅛ inch diameter. The filter cap 56 is inserted into thebarrel valve 36 along axis 14 until shoulder 69 on the filter cap abutthe shoulder and rotated, which causes locking tabs on the filter cap 56to engage locking stops on the barrel valve 36 to rotate the barrelvalve until locking tabs on the barrel valve engaging locking stops onthe manifold head in a use position in which the fluid passages to thefirst (inlet) fitting 30, second (outlet) fitting 34 and middle ventfitting 105 are aligned so fluid can flow through them. The preferredfluid flowing through the various vent passages disclosed herein, isgas. A rotation of the barrel valve 36 of about 30 degrees is believedsuitable for the barrel valve locking tabs to engage the manifold headstops, and a rotation of the filter cartridge of about 30 degrees isbelieved suitable to engage the filter cap locking tabs with the stopson the barrel valve, so the filter cartridge rotates a total of about 60degrees—preferably clockwise, during installation. To disengage thefilter cartridge, the cartridge is rotated the opposite direction (e.g.,counterclockwise) which causes the barrel valve 36 to rotate the samedirection (e.g., counterclockwise) until the valve body hits a positionstop at which point the filter cap continues to rotate the samedirection (e.g., counterclockwise) until the locking tabs on the filtercap clear obstructions in the valve body so the filter cap and cartridgecan be removed along axis 14 from the barrel valve 36 and manifold head10.

FIGS. 4 and 5 show a plurality of filter manifold heads 10 connected toother manifold heads. The manifold heads may be connected in series(FIG. 4) or parallel (FIG. 5), or a mixture of both if desired (notshown). For the parallel connection of FIG. 5, all of the first fluidpassages 30 are connected to a common first fluid passage and all of thesecond fluid passages are connected to a different but common fluidpassage. Thus, the first fittings 30 are connected by a first coupling110 to a first tube 112 which connects to each first coupling 110. Thedepicted coupling 110 is an elbow coupling having a first couplerconnected to and axially aligned with a distal end of the first fitting30 while the while other end of the coupling 110 has another couplerconnecting to another tube (here series tube 118). The second fittings34 are connected by a second coupling 114 which connects to a secondtube 116 in a manner similar to the first coupling 110, the descriptionof which is not repeated.

Any number of manifold heads may be coupled. In the depicted embodimentfirst manifold head 10 a has its first fitting 30 a in fluidcommunication with first coupling 110 a and first tubes 112 a and 112 b.The second manifold head 10 b has its first fitting 30 b in fluidcommunication with first coupling 110 b and first tubes 112 b and 112 c.The third manifold head 10 c has its first fitting 30 c in fluidcommunication with third coupling 110 c and first tube 112 c. The firstcouplings 110 a and 110 b are T fittings while coupling 110 c is anelbow fitting since manifold head 10 c is at one end of the line ofmanifold heads connected by first tube 112. Likewise, first manifoldhead 10 a has its second fitting 34 a in fluid communication with secondcoupling 114 a and second tubes 116 a and 116 b. The second manifoldhead 10 b has its second fitting 34 b in fluid communication with secondcoupling 116 b and second tubes 116 b and 116 c. The third manifold head10 c has its second fitting 34 c in fluid communication with secondcoupling 114 c and second tube 112 c. The second couplings 114 a and 114b are T fittings while coupling 114 c is an elbow fitting since manifoldhead 10 c is at one end of the line of manifold heads connected bysecond tube 116.

For the series connection of FIG. 4, the first fitting 30 of onemanifold head 10 is in fluid communication with the second fitting 34 ofa different manifold head. Thus, the second fitting 34 a of manifoldhead 10 a is connected to tube 18 a by second coupling 114 a, while thefirst fitting 30 a is connected to a different tube 18 b by firstcoupling 110 a. The tube 118 b is connected to second fitting 34 b ofdifferent manifold head 10 b by second coupling 114 b. The first fitting30 b of manifold head 10 b is connected to first coupling 110 b and tube118 c. The tube 118 c is connected to the second fitting 34 c ofmanifold head 10 c. The first fitting 30 c of manifold head 10 c isconnected to first coupling 110 c and tube 118 d. Thus, fluid flowsthrough all the manifold heads 10 a, 10 b, 10 c in series through thecouplings 114 and tubes 118.

Referring to FIGS. 6-7 and 11-12, the middle vent passage may beextended through the wall of the barrel valve (when present) and throughthe wall of the filter cap 56. The filter cartridge has two, spacedapart seals 130, 132 (FIGS. 7, 12) on the neck 134 of the filtercartridge 55 to form a filter nozzle void volume between the seals 130,132 and the adjacent and facing parts of the neck 134 and the innersurface of filter cap 56 bounded by and sealed against those two seals130, 132. The filter cap has a generally cylindrical first filter capinner surface forming cavity 70 into which the nozzle and seals 330, 132of the cartridge 55 fit. Most of the parts are as described above andthat description is not repeated. But the middle vent passageway isextended by filter cap vent passage 136 which extends through the wallof the filter cap 56 at a location which aligns middle vent passages136, 102, 100 during use to form an access, preferably a direct,straight line access, to the filter nozzle void volume. The middle ventpassages 100, 102, 136 are preferably a single aligned passage forsimplicity of manufacture, with the passages passing through voidvolumes between each of the nested parts and preferably opening betweenthe two spaced apart seals 130, 132. As the barrel valve 36 may beomitted in some configurations, the passageway 102 may be omitted insome configurations. Advantages of venting the filter nozzle void volumeare discussed below.

Referring to FIG. 7, additional vents can be added to not just themiddle void volume(s), but to the top and bottom void volumes, to eithermonitor leaks, confirm the lack of leaks, vent moisture, or introducegas or fluid between the seals bounding inlet or outlet flow channels.The middle vent described above regarding FIG. 6, may be extended asshown in FIG. 7 to vent the void volume between the two, axially spaced,upper and lower nozzle seals 130, 132 on the tubular neck 134 of thefilter cartridge 55 which tubular neck forms the fluid path to firstfilter cap openings 68 and first filter cap fluid channel 66. The seals130, 132 may be referred to as spaced apart nozzle seals on the outersurface of the nozzle on the filter cartridge 55. The void volumebetween the seal 64 which seals the lower side of flow channel 66 andseal 72 which seals the top side of the flow channel 76 is vented bypassages 100, 102 and middle vent fitting 105. The seals 130, 132provide a fluid seal with the inside generally cylindrical cavity thatis preferably formed inside upper portion of filter cap 56 and intowhich the neck 134 of the filter cartridge is removably inserted duringuse. Conventional filter cartridges often have a single seal on thenozzle 134 instead of the pair of spaced-apart seals 130, 132. Thenozzle seals 130, 132 are spaced apart a distance sufficient to form afilter nozzle void bottom between the nozzle seals 130, 132 and theadjacent and facing walls of the nozzle 134 and filter cap 56 locatedbetween those nozzle seals. That filter nozzle void volume is vented byfilter cap vent passage 136 in fluid communication with the other middlevent passages 100, 102. Preferably, the nozzle seals 130, 132 are spacedapart a distance of about 3/16 inch or more as measured between theclosest portions of the grooves containing the seal members, in order toallow a filter cap vent passage 136 of about ⅛ inch to vent the voidvolume and allow for axial positioning errors along axis 14.

The filter cap vent passage 136 may be formed through one side of thefilter cap 56, preferably through the lower, second portion 40 of valvebody 36. The filter cap vent passage 136 preferably accesses a voidvolume formed between two seals on the filter nozzle in cavity 70 of thefilter cap, and may be referred to herein as the nozzle vent passageway136 or as filter cap middle vent passage 136. The vent passage 136 ispreferably a radial oriented passageway aligned to be placed in fluidcommunication with, and preferably along a common longitudinal axiswith, the barrel valve vent passage 102 through the barrel valve andmanifold vent passage 100 through the manifold head, during use of thefilter cartridge 55. The seals 130, 132 provide a seal on opposing sidesof the filter nozzle void volume formed between those seals 130, 132 andbetween the neck 134 and the upper portion of the filter cap 56. Thefilter cap vent passage 136 passes through the wall of the filter cap 56and is in fluid communication with that filter nozzle void volume. Thevent passages 136, 102, 100 may be aligned to provide direct access tothe filter nozzle void volume bounded by nozzle filters 130, 132 thatare interposed between the nozzle and the mating surface of the filtercap 56.

Extending the middle vent passage to the filter nozzle void volume byaligning middle vent passages 100, 102, 136 provides multiple advantagesand allows several uses. If there is a leak between the filter neck 134and the filter cap 56 through seals 130, 132 then fluid will passthrough the middle vent passages 100, 102, 136 and may be detected. Thisalso allows testing the seal on the neck 134 of the filter cartridge 55.A leak sensor may be passed through a portion of or all of the alignedpassageways if desired to expedite fluid transfer through middle ventfitting 105 or one or more of middle vent passages 100, 102, 136 formingthat vent path. Similarly, if fluid is leaking into the void volumebetween seals 72 b, 74 b around channel 66 and between the filter cap 56and the barrel valve 36 then the leak may be detected. Likewise, iffluid is leaking into the void volume between seals 104 b, 106 b whichare interposed between the barrel valve and the manifold head that leakmay be detected.

Still referring to FIG. 7, a top vent passage may also be provided. Seal42 b encircles the top end 46 of barrel valve 36 forming a top, barrelvalve void volume between the top end 46 and the inside of the end wall16 of the manifold head and the periphery of the seal 42 b. A top ventmanifold vent fitting 140 has a top manifold top manifold vent passage142 extending through the fitting 140 and through the wall of themanifold head 10. The top manifold vent passage 142 is preferablygenerally cylindrical and extends radially through a side wall of thefirst portion 18 of the manifold head adjacent top wall 16.

A top filter cap void volume is formed between the top surface of top 86of the filter cap 56 and the bottom surface of the top end 46 of barrelvalve 36, with seal member 62 b encircling the filter cap 56 to boundthe filter cap void volume. The seal member 62 b cooperates with sealmember 62 b to bound the flow channel 66, with the periphery of upperseal member 62 b also preventing fluid from channel 66 from flowing intothe top filter cap void volume when all parts work as intended. A topvent passage 144 extends through the top end 46 of barrel valve 36 toplace the top filter cap void volume in fluid communication with the topbarrel valve void volume, which is in fluid communication with top ventfitting 140 through top vent passage 142. If the top vent fitting 140were formed parallel to axis 14 the vent passages 142, 144 could beaxially aligned. But placing fitting 140 radially provides a reducedheight assembly. If the top vent fitting 140 extended radially through asidewall of the filter cap at a location above the top seal member 62 bthen the passages 142, 144 could be radially aligned, but doing soincreases the height of the filter cap as the seal member 62 b must bebelow the passage 144, and that increase in height is not preferred.

The lower seal member 74 b encircles the filter cap below the channel76. The gap between the mating filter cap 56 and barrel valve 36 mayvent to atmosphere through the labyrinth path between the nested filtercap and barrel valve. But in the embodiment of FIG. 7 the axial lengthof the lower, second portion 60 of the filter cap 56 is increased as isthe axial length of the second portion 40 of the barrel valve 36, as isthe length of the second portion 20 of the manifold head 16. A filtercap base seal 90 is placed between the second portions 40, 60, andpreferably comprises an O-ring seal 90 a in a groove 90 b formed in thesecond portion 60 of the filter cap. The seal 90 (or more accuratelysealing member 90 b) forms a bottom filter cap void volume that containsthe gap between the second portions 60 and 40 of the filter cap andvalve body, respectively. The ends of that gap are sealed by lower sealmember 74 b and filter cap base seal 90 to form the bottom filter capvoid volume. A barrel valve base seal 152 is place between the secondportions 40, 20 and preferably comprises an O-ring seal in a grooveformed in the second portion 40 of the barrel valve.

The seal 90 forms a bottom filter cap void volume that contains the gapbetween the second portions 60 and 40 of the filter cap and valve body,respectively. The top and bottom ends of that gap are sealed by lowerseal member 74 b and filter cap base seal member 90 b respectively, toform the bottom filter cap void volume. The seal 152 forms a bottombarrel valve void volume that contains the gap between the secondportions 20 and 40 of the manifold head and valve body, respectively.The top and bottom ends of that gap are sealed by the lower seal 44 band barrel valve base seal 152, respectively, to form the bottom barrelvalve void volume.

Lower vent fitting 158 extends outward from second portion 20 ofmanifold head 10. Bottom manifold vent passageway 156 is formed throughthe fitting 158 and through the sidewall 12 of the manifold, preferablythrough the second portion 20 of manifold head 10. The bottom manifoldvent passageway 156 is preferably a radially oriented generallycylindrical passage, but as with the other vent passages, could havediverse shapes. The bottom manifold vent passageway 156 is in fluidcommunication with the bottom barrel valve void volume. A bottom barrelvalve vent passageway 154 extends through the second portion 60 of thefilter cap 46 and is in fluid communication with the bottom filter capvoid volume and with the bottom manifold vent passageway 156. The bottomvent passageways 154, 156 are preferably radially aligned along a commonlongitudinal axis, but need not be so aligned. A face seal 155 may beformed in one of the barrel valve or manifold encircling one of thepassageways 154, 156 to provide a fluid tight seal between those partsbut allowing fluid to flow through the passageways 154, 156. The seal155 is shown as formed in the barrel valve 36.

The top vent passages 144, 142 and the bottom vent passages 154, 156 maybe used in any or all of the same ways as the middle vent passages 102,100 to test for leaks or seepage into the void volumes accessed by thepassages, or to test leaks or weeping past the seals forming the voidvolumes. As desired, wicking members, capillary action members or othersensor materials may be placed in any of the passages to identify leaksor weeping past the seals. Further, the passageways may be used with airor other gases to test the seals forming the void volumes connected bythe passageways, or the passageways may be used with air or other gases,at various temperatures, to dry the void volumes in fluid communicationwith the passageways, especially to reduce bacterial or mold growth inthe void volumes. The passageways may be used in any combination toaccess any void volume.

The carbon filters used in most filter cartridges 55 absorb air so apressure decay test or flow test monitoring the pressure or flow changebetween first and second fittings 30, 34 is difficult to accuratelyperform. Filter cartridges may be individually tested for leaks in adunk tank where leaks are identified by bubbles forming at the locationof the leak. But these tests require drying the cartridges after testingand risk contamination by the water used in testing and possiblebacteria growth, thus discouraging the comprehensive testing ofindividual cartridges for leaks. Testing is thus by random samplingrather than individual testing of each filter cartridge 55 produced. Itis believed that fewer than 5-10% of filter cartridges for appliancesfrom an assembly line or production facility undergo testing. Referringto FIG. 7, the middle vent passage 100, 102, 136 allows testing the sealcapability of the two, spaced apart nozzle seals 130, 132. The presentimprovements allow individual testing of the most likely leak locationsof each cartridge produced, and readily allow testing half or more ofthe cartridges produced, and more preferably allow testing of over 90%of the cartridges produced.

The void volume between seals 130, 132 and the parts mating the innerand outer sides of those seals 130, 132 may be accessed through themiddle vent passage 100, 102, 136, or combinations thereof—depending onwhether the barrel valve and/or manifold head are present in theparticular configuration in which the filter cartridge 55 is used. Thevoid volume between the seals 130, 132 b may be pressurized with a testfluid (gas and/or liquid) to see if the test fluid passes the seals 130,132 with monitors at the first and second fittings 30, 34 or elsewherealong the flow paths in fluid communication with those fittings 30, 34.Because the void volume being pressurized is small the testing can beperformed quickly and with small volumes of gas. While the pressurizedvolume is in the void area the tested seals or O-rings bound at leastone side of the fluid flow path. As used herein, the term “pressurized”includes both positive pressure and negative pressure (i.e., partialvacuum or vacuum or suction). The small volume allows eitherpressurization method to quickly test the seal integrity, preferablyrequiring a few seconds per cartridge, and more preferably less than 5seconds per cartridge to apply the pressure and monitor the pressure toevaluate the seal integrity.

Tracer gases such as noble gases may be used as test fluids with gasdetectors used at the first and second fittings 30, 34. Alternatively, atest fluid, preferably a gas such as air, may be applied to the first orsecond fittings 30, 34 and the nozzle void volume accessible through themiddle vent passage 100, 102, 136 can be checked for the presence of thetest fluid (e.g., pressure increase) to evaluate the effectiveness orintegrity of the seals 130, 132 and that does not depend on theabsorption of the test fluid by the carbon filter. Using test gascompatible with the filter's use (e.g., helium, nitrogen, argon or othergases) and detectable by a sensor in communication with middle ventpassage 100, 102, 136 is also believed suitable.

Alternatively, because the middle vent passage 100, 102, 136 connectsvoid volumes which are bounded by seals between mating parts, thepressure decay of a test fluid placed in the middle vent passage may bemonitored to test the effectiveness of the seals present in the systembeing tested. A flow test may also be used which measures the rate offlow needed to maintain a specified pressure applied to the middle ventpassage. In addition to this testing, the vent passages offer thepossibility of applying a positive pressure during use to reduce seepageor the possibility of flowing a drying gas during use to reduce growthof bacteria or mold or simply venting the void volume to ambientatmosphere to dry the void volumes. The vent passages communicating withambient atmosphere may also allow moisture weeping past the sealsdefining the void volumes associated with the particular vent passage inquestion to evaporate and thus reduce or eliminate growth of bacteria ormold.

Similar tests may be performed using the top vent passage 142, 144 totest the integrity of seals 42 b and or 62 b forming the void volumesplaced in fluid communication with the passages 142, 144. Likewise,similar tests may be performed using the bottom vent passage 156, 154 totest the integrity of seals 74 b, 44 b forming the void volumes placedin fluid communication with the vent passages 154, 156. Note that eachof the void volumes has one seal which forms part of the flow passage influid communication with either the first fitting 30 or second fitting34 and their associated flow paths through the filter cartridge. Thecentral or middle void volume has two seals that form part of the flowpassage in fluid communication with one of the fittings 30, 34. Thus, byusing various combinations of one or more of the top, middle or bottomvent passages the seals defining fluid flow through the filter cartridge54 may be tested. By performing such testing with a gas, such as air, aninert gas or other detectable gas compatible with the filter cartridge'suse, each individual cartridge may be tested for leaks at the seals.

Because the void volumes are small the pressurization of the void volumemay be achieved quickly and with small volumes of test gas. The pressurein the void volume may be monitored to see if the seals defining thevoid volume being tested leak because a leak would lower the testpressure while no pressure drop or a suitably low pressure dropindicates no leakage or acceptable leakage. Alternatively, the flow ofgas needed to maintain the test pressure may be monitored and used toreflect the existence and size of a leak, with a low flow or no flowrate indicating an acceptable leak or no leak, and a higher flow rateindicating an unacceptable leak. If the seals defining the void volumehold pressure that indicates the seals don't leak. If the seals don'tleak when the void volume is pressurized the same seals shouldn't leakwhen the fluid path defined by the void volume is filled withpressurized water. Thus, by pressurizing the void volumes and testingfor leaks in the direction opposite the direction in which water wouldleak during use, the leakage during use is tested.

Instead of pressurizing the void volume with a test gas the filter canbe pressurized with a test gas and the void volumes monitored to see ifthe pressure increases and reflects a leak or the void volume can bemonitored to detect the presence if the test gas and optionally to testthe amount of test gas in the monitored void volume as that reflects thesize of the leakage. But pressurizing the cartridge requires more volumeof test gas and the test gas may be absorbed by the filter and bothaspects need to be taken into account if the entire cartridge ispressurized. Thus, if the absorption of the test fluid by the filterelement is taken into account the testing may also include testing forleaks of the cartridge housing itself. Since the filter may retain thetest gas, the test gas is preferably inert.

Air is a preferred test gas because of its ready availability and lowcost. Nitrogen is a preferred test gas because of its inertness, but thenitrogen molecules are slightly larger than a water molecule so the leaktesting is not completely accurate. Helium is a preferred test gasbecause of its inertness but the helium molecules are smaller than watermolecules and that has the advantage of detecting even small leaks butthe results are more conservative since leaks that occur with helium maynot occur with water.

The leak testing can be achieved by inserting the filter cartridge 55and neck 56 into a test head simulating, and preferably replicating theseals of the barrel valve or manifold head to be used with the filtercartridge. The test head would of course be provided with vent passagesat the desired location of the void volume or volumes used for testing.Depending on the test arrangement the test head would also be providedwith gas detectors (or fluid detectors if liquid is used) at appropriatelocations in the void volumes or in the flow passages, depending on thetest arrangement and what volumes were being pressurized with test gasand how leakage was being tested. If a test head is used then the filtercap 56 may omit seals 90 and test the filter cap by having the test headprovide the lower seal 90 to create the bottom filter cap void volumebounded on the upper side by seal member 74 b.

As shown in FIG. 6, the vent passages 100, 142 and 156 are preferablyslightly tapered in diameter through the fittings 105, 140, 158,respectively. The taper is believed to make it easier to mold themanifold head 10, which is preferably molded of a suitable plasticmaterial.

The prior art filter cartridges used two or three O-ring seals to formtwo flow paths with the middle O-ring seal separating the two flowpaths. Depending on the filter construction the first flow path could bethe inlet or the outlet flow path, with the second flow path being theother (the outlet or the inlet flow path). The above describedconstruction uses four seals (62, 64, 72, 74), preferably O-ring seals,to form the two, first and second flow paths, resulting in two sealsdefining each flow path and a middle void volume between the middle twoseals 64, 72. That middle void volume is preferably vented to a locationoutside the manifold head, by passages 100, 105 exiting through middlefitting 105, with the vent passage preferably extending to the nozzlevoid volume formed between nozzle seals 130, 132—by vent middle ventpassage 136 or nozzle vent passage 136. The top filter cap void volumeformed by top seal 62 interposed between the filter cap 56 and barrelvalve 36 is preferably vented to a location outside the manifold head,by passages 144, 142 exiting through top fitting 140. The bottom filtercap void volume formed by seal 40 and seal 90 interposed between thefilter cap 56 and barrel valve 36 is preferably vented to a locationoutside the manifold head by bottom vent passages 154, 156 exitingthrough bottom fitting 158. The passage 156 also vents the bottom barrelvalve void volume formed by seals 44 and 152 interposed between thebarrel valve 36 and the manifold head 10.

To expedite the identification of leaks or weeping, and to reduce thetesting time, the void volume is preferably made as small as reasonablypractical so that leaked test fluid passing one of the seals definingthe void volume being vented is more quickly forced or transmitted to alocation where it may be detected. Thus, the gap between the matingparts forming the void volumes is preferably small, but still largeenough to make assembly of the mating parts practical for the user ormanufacturer to make and/or assemble, depending on the part. The sealsbounding the flow paths in fluid communication with first and secondfittings 30, 34 and their associated flow paths are preferably as closetogether as practical to achieve the desired flow rate into and out ofthe filter cartridge. The vent passages are preferably small in order toallow a small amount of test fluid or water leaked during use to be morereadily passed through the vent passages and detected. A diameter ofabout ⅛ inch is believed suitable for water filter cartridges 55 forhousehold and small commercial uses, including refrigerators.

The first fluid passage 28, 48, 66 and 36 may form either a fluid inletof unfiltered fluid to the filter cartridge 55 while the second fluidpassage 78, 76, 52 and 32 forms a fluid outlet from the filter cartridge55, or vice versa. The details of the fluid flow paths through thefilter element 59 will vary with the particular configuration andlocation of the inlet, filter and outlet of the cartridge 55. But unlessthere is a bypass mechanism inserted into the manifold body 10, it isnot desirable to have water flow through the manifold when no filtercartridge is in the manifold body 10. The depicted embodiment isconfigured to block flow when the filter cap and cartridge are removedand to open flow when the filter cap and cartridge are in the operativeposition, with the positions achieved by various lugs or tabs extendingfrom the valve body and filter cap.

The filter cap 56 has filter cap locking lugs 160 extending outward fromthe periphery of base 82 of the filter cap. The base 82 is preferablycircular with the filter cap locking lugs 160 extending outward from theperiphery of the base 82 and preferably in the same plane as to base 82.The locking lugs 160 preferably extend a short distance, with a distanceof about ⅛ to ¼ inch believed suitable, but the length can varyaccording to design. Preferably two equally spaced and opposing filtercap locking lugs 160 are used and they extend in the radial directionrelative to longitudinal axis 14. More than two locking lugs 160 may beused as desired, with three and four locking lugs being known in theart.

The upper surface of the base 82 and each of the locking lugs 160 have achannel 162 extending along the length of and formed in the locking lugand base. A U-shaped channel 162 with opposing parallel sides and a flatbottom is shown and believed preferable. The channel 162 preferablyextends along a radial direction relative to axis 14, along the centerof each locking lug. Advantageously the bottom of filter cap 56 has acircular base 82 with inwardly stepped shoulders forming circular bossesof decreasing diameter below the base. The body of the filter cartridge55 enclosing the filter material has an open end that advantageouslyabuts one or more of the stepped shoulders as is known in the art and isfastened thereto to form a water tight connection as is known in theart. An adhesive connection, a melted connection formed by frictionwelding, spin welding, or ultrasonic bonding is believed suitable.

Referring to FIGS. 3 a, 3 b and 10 a, 10 b and 10 c, the locking lugswhich hold the filter cap 56 to the barrel valve 36 and manifold head 10are described along with an improved connecting mechanism to releasablyconnect and rotate the filter cap with the barrel valve. The base ofbarrel valve 36 has outwardly extending flange 41 which is shown as agenerally annular flange extending radially outward. From at least one,and preferably from two or more equally spaced locations on theperiphery of the flange 41 extend barrel valve locking lugs 164, withthe flange 41 and lugs 164 preferably extending in a direction radial toaxis 14. The barrel valve locking lugs 164 may match the number andlocation of filter cap locking lugs 160 on the filter cap, but that neednot be the case. The barrel valve locking lugs have a downwardlyextending flange 166 that advantageously extends a distance about thesame as or slightly more than the axial thickness of the filter caplocking lugs 160.

Extending axially away from the bottom of the barrel valve 36 are one ormore channel tabs 168. The channel tabs 168 are sized and located to fitinto the channel formed in base 82 and filter cap locking lugs 160. Thechannel tabs 168 are thus preferably rectangular in shape and extend adistance about the same as the depth of the channel 162 in the base 82and locking lugs 160 when the filter cap 56 is nested inside barrelvalve 36 during use.

Referring to FIGS. 3 and 8-10, the barrel valve 36 has its locking lugs164 setting in and retained in the manifold base 11 by a generallycylindrical wall 170 extending upward from the base 11 and encircling anopening 172 through which the filter cap is inserted into the manifoldbase 11 from the bottom side of the base 11. The generally cylindricalwall 170 is slightly larger in diameter than the distance between theopposing ends of the barrel valve locking lugs 164. The manifold opening172 is large enough so the filter cap 56 can fit through the opening andmate with the barrel valve 36 during use. The generally cylindrical wall170 is larger than the opening 172 so the manifold base 11 forms ahorizontal lip or ledge or locking surface 27 on which the flange 166 ofthe barrel valve locking lugs 164 can rest and rotate during use. Thewall 170 centers the barrel valve 36 on the opening 172. The manifoldbody 10 is positioned so its circular mounting flange 24 rests againstthe top of the generally cylindrical wall 170 to form a cavity in whichthe barrel valve locking lugs 164 are trapped for rotation.

The opening 172 is generally circular but has two (or possibly more)filter lug openings 173 (FIG. 10 a, 10 b) located to coincide with thelocation of the filter cap locking lugs 160. In the depicted embodimentthere are two filter cap locking lugs 160 on opposing sides of thefilter cap so there are two filter cap lug openings 173. The lug opening173 is a generally rectangular arc extending radially outward beyond thediameter of the filter cap opening 172 in order to accommodate thepassage of the filter cap locking lugs through the lug openings 173along the axis 14 during use, as described later.

The barrel valve body 10 is positioned by cooperative alignment of analignment hole 174 in or through the mounting flange 22 on the manifoldwhich cooperates with a positioning pin 176 extending upward from themanifold base 11. There are preferably at least two alignment holes 174and mating positioning pins 176 for each manifold 10 when the manifoldsare separately attached to the base plate. As seen in FIG. 10 a, fouralignment pins 176 are preferred so there are preferably four alignmentholes 174. Fewer can be used if multiple manifolds are formed in asingle piece assembly. Once the barrel valve body 36 is placed in thespace encircled by wall 170 on the manifold base 11, the manifold flange22 is aligned with the manifold wall 10 and the manifold 10 is fastenedto the base so as to trap the barrel valve body 36 in the cavity formedby the flange 22 and wall 170. The fastening may be mechanicalfasteners, welding, adhesives, melting or other connecting mechanisms.The parts are aligned so the manifold body 10 and barrel valve body 36are aligned along the longitudinal axis 14. That construction allowsbarrel valve body 36 to rotate within the manifold 10 but restrainsaxial motion along longitudinal axis 14 and restrains lateral motion inthe plane of the manifold base 11. Similar constructions which enclosethe periphery of the barrel valve body 10 within a shaped cavity toeffectively restrain all motion of the valve body except rotation aboutaxis 14 may also be used. These constructions provide means forrotatably mounting the barrel valve body between the manifold body 10and manifold base 11. In this configuration the channel tab 168 (FIGS. 3a and 8) extends downward.

The barrel valve 36 rotates between a first position blocking flow tothe filter cap and a second position allowing flow to the filter cap.Referring to FIGS. 3 and 9-10, the barrel valve locking lugs 164 have afirst movable stop face 178 a on diagonally opposing corners of each lug164 and flange 166 as best seen in FIG. 3 a. The movable stop faces 178a face opposing directions. As best seen in FIGS. 9 and 10, the manifoldbase 11 has first and second pairs of shaped bosses 180, 181. The firstbosses 180 are on diametrically opposing sides of wall 170 as are thesecond bosses 181. Each first boss 180 is about 90° from the adjacentsecond boss 181, in either the clockwise or counterclockwise direction.

Advantageously, a positioning pin 176 extends from each boss 180, 181.The first bosses 180 also form a first stationary stopping face 178 b onthe base 11. The first stationary stopping face 178 b on the firstbosses 180 are each located adjacent to but inside of the wall 170 so asto be in the circular path that the distal end of the barrel valvelocking lug 164 rotates and abutting stopping face 178 a. The two,second stopping faces 178 b face opposing directions, one facingclockwise and the other facing counterclockwise. The stopping faces 178a, 178 b are preferably inclined at the same angle so they abut along aflat surface when the faces contact each other. In the depictedembodiment the movable stopping faces 178 a are at an angle of about 45°to the tangent of the barrel locking valve lug 164 on which the stoppingfaces 178 a are formed.

Advantageously, the bosses 180, 181 extend inward of the wall 170 so asto block rotation of the locking lugs 164 in either direction but notfar enough to extend into the opening 172. On the opposing side of eachfirst boss 180 but within the wall 170 is a second, stationary stoppingface 182 facing in the opposite direction as the first stopping face 178b. The second stopping face 182 may have various orientations but isshown as extending along a radial line from longitudinal axis 14. Asseen in FIG. 10 b, there thus two first bosses 180, diagonally oppositeeach other and each having a first, stationary stopping face 178 blocated on one side of the boss 180 and second, stationary stopping face182 on an opposite side of boss 180.

Each of the second bosses 181 also has a stationary stopping face 184.Each stationary stopping face 184 is at a distal end of a different oneof the filter cap lug openings 173. As seen in FIGS. 10 a, 10 b, thebosses 180, 181 have opposing radial stopping faces 182, 184 at opposingends of an arc of the wall 170, on diametrically opposite sides of thewall and on opposing sides of opening 172 in base 11.

Referring to FIGS. 3 b, 10 a and 10 b, each filter cap locking lug 160has two rounded distal corners 186 a, 186 b, on opposing sides ofchannel 162. The corners 186 a, 186 b form position stops for the filtercap locking lugs 168.

Referring to FIGS. 3 and 8-13 the mating of the filter cap with themanifold and the operation of the locking lugs is described. In use thevalve body 36 is placed inside the manifold 10 which is fastened tomanifold base 11 so as to contain the valve body 36 between the manifoldbody 10 and base 11 so the valve body can rotate about axis 14 but notmove laterally or axially and cannot rotate except about axis 14. Thefilter cap 56 (and connected cartridge 55) is inserted into the centralcavities of the manifold 10 and advanced along longitudinal axis 14 ofthe mated manifold and valve body, with the filter cap locking lugs 64each fitting through a different one of the cap lug openings 173. Whenthe filter cap locking lugs 160 advance axially through the opening 11past the plane of the manifold base 11 then the filter cap (and filtercartridge 55) are positioned with the stationary stopping faces 184 onboss 181 aligned with one of the stopping faces 186 on the filter caplocking lug 160. The stop faces 178 a, 178 b on the barrel valve andboss 180 are contacting each other to position the barrel valve relativeto the manifold body 10 and base 11. As the locking lug 160 of filtercap 56 passes through opening 11 the barrel valve 36 is oriented so thatthe channel tabs 168 on the bottom of the barrel valve fit into andreleasably engage or mate with the channel 162 in filter cap base 82 tointerlock the barrel valve 36 and filter cap 56 for rotation about axis14.

In this first, closed configuration (FIG. 10 a) the flow through themanifold and valve body is blocked so there is no flow through the valvebody 36. Referring to FIGS. 1, 6, 7, 11 and 12, flow through fittings30, 34 requires alignment of manifold flow passages 28 and 32 on themanifold body 10 with the barrel valve flow passages 48, 52 in thebarrel valve body 36. When the barrel valve 36 is rotated about axis 14the barrel valve flow passages 48, 52 are rotated out of alignment withmanifold flow passages 28, 32 and no flow occurs through the valve body36. The seals 50, 54 seal between the rotating valve body 36 andstationary manifold body 10 to prevent leakage as the barrel valverotates. Then the valve body is rotated to the second, open position thebarrel valve flow passages 48, 52 are aligned with manifold flowpassages 28, 32 through the manifold 10 to allow flow.

In this first, closed position (FIG. 10 a), rotation of the filtercartridge 55 and filter cap 56 in a first direction is blocked byabutting stopping faces 184 on bosses 181 and stopping faces 186 on thefilter cap locking lugs 160, and is also blocked by abutting stoppingfaces 178 a, 178 b on the valve body 36 and manifold base 11,respectively to position the valve body relative to the mounting plate11 and tab openings 164. The abutting stops provide a noticeableresistance to further rotation and indicate to the user that the partsare in this closed position where no water flows and the cartridge andfilter cap may be removed or inserted without water leakage.

In this first, closed position when the channel tab 168 on barrel valve36 mates with the channel 162 in the filter cap 56, the fluid passagesthrough the filter cap and barrel valve are aligned to allow flowthrough passages 50, 52 and into channels 66, 76 and associated openings68, 78 through the filter cap and into chambers 70, 80 of the filtercap. This is shown in cross-sectional view of FIG. 12. Thus, the filtercap 56 and barrel valve 36 have an alignment mechanism to align flowpaths through the filter cap and barrel valve.

Rotation in the second, opposing direction to a second, open positioncan be achieved with the engaged or interlocked channel tabs 168 on thebarrel valve 36 and channel 162 on filter cap 56 causing the filtercartridge 55, filter cap 56 an barrel valve 36 rotating together aboutlongitudinal axis 14. These parts rotate together in the seconddirection about 90° to a second position in which the stopping faces 186on filter cap locking lugs 160 hit the stopping faces 182. The abuttingstops 186, 184 provide a noticeable resistance to further rotation andindicate to the user that the parts are in a position where water canflow through cartridge and filter cap.

In this second, open position (FIGS. 1, 6, 7, 10 b, 11, 12 and 13 a) thefluid channels are aligned so water flows through the manifold, valvebody, filter cap and filter cartridge. This position is shown in FIGS.11-12, as well as other figures. As the interlocked valve body 36 andfilter cap 56 are rotated in this second direction toward the secondposition, the filter cap locking tabs 160 and barrel valve locking tabs64 are both sliding on the short lip 27 on the manifold base 11 locatedbetween the opening 172 and wall 174. This may be seen in thecross-sectional view of FIG. 12. The flange 166 on each end of thebarrel valve locking tab 164 slides on this lip 27 since the barrelvalve is trapped in the cavity between the manifold body 10 and manifold11 to restrain the barrel valve body 36 to rotation about axis 14. Thisis shown in FIG. 11. Those flanges 166 and barrel valve locking tabs 164are located about 90° from the filter cap locking tabs 160 which fitthrough tab openings 173 and are rotated into engagement with the lip 27surrounding filter cap opening 11. Because the axial forces (alonglongitudinal axis 14) are so low, the filter cap locking lugs 160 can bethinner than usual and can accommodate the channel 162 which furtherweakens the locking lugs 160.

Because the thickness of locking lugs 160, 164 and the mating lockingsurface 27 vary with the filter diameter, water pressure and calculationsafety factor, it is difficult to precisely define how thin these matinglocking surfaces can be. Some examples help illustrate the proposed sizereduction. A filter cartridge 55 with a one inch diameter openingencircled by an O-ring seal has an opening area of about 0.8 squareinches. A typical design with a safety factor and based on industrystandard testing up to 150 psi pressure may result in a higher designpressure in order to provide a safety factor. It is common to testfilter cartridges to a maximum burst pressure of 500 psi and in order toensure the cartridges do not burst every time they are tested the designpressure may be 600 psi. For the one inch diameter filter cartridge 55that results in a design force of about 600 psi×1.76 in²=1,056 pounds,or about 1100 pounds of axial force to be withstood by the various lugsand mating surfaces. But with the lugs using the radial flow designdisclosed herein the design may focus on withstanding the weight of thecartridge and the use where the cartridge is twisted into and out of thevalve body and manifold so that it is believed that the using lugs andmating surfaces of the current radial flow design may be designed towithstand about ¼ to ⅕ the typical forces. Thus, the lugs and matingsurfaces may be designed to resist about 500/5=100 (or 125 pounds for a¼ factor) instead of about 500 pounds. Likewise, if the opening areaincreases to 1.76 square inch as may arise in some residentialapplications the design load may decrease from about 1100 pounds toabout 220 or 275 pounds for a 5 fold or 4 fold reductions in the load.In either case, the design load on the lugs and mating surfaces arereduced by over 50%, and preferably reduced from about 75-80% comparedto typical designs used today.

To remove the filter cartridge the sequence is reversed, with thecartridge 55 and filter cap 56 being rotated about longitudinal axis 14in the first direction toward the first position in which the stops 178a on the flanges 166 and lugs 164 of barrel valve 36 abut stops 178 b onthe manifold base 11 to position the barrel valve 36 relative to themanifold base 11, and in which the stopping faces 186 on filter caplocking lugs 162 abut stopping faces 184 on the bosses 181 of manifoldbody 11 to position the filter cap 56 relative to the manifold base 11and tab openings 173. The filter cartridge 55 is then pulled alonglongitudinal axis 14 to disengage channel tab 186 on the barrel valve 36from channel 162 on the filter cap 56 and to remove the cartridge andfilter cap from the manifold 10 and barrel valve 36.

There are thus provided at least one and preferably two or more firstpositioning stops 174 a, 174 b on the valve body 56 and manifold 10, 11to position the valve body in a first position in which flow through thevalve body 56 is closed. There are also provided at least one andpreferably two or more second positioning stops 184, 186 on the filtercap and manifold 10, 11 to position the barrel valve 36 so thatinsertion of the filter cap 56 into the barrel valve aligns the fluidpassages of the barrel valve with the fluid passages through the filtercap, with the positioning stops 184, 186 further aligning the matingchannel tab 168 and channel 162 on the valve body and filter cap,respectively, to interlock those parts for rotation about axis 14.

Referring to FIG. 13 b, to rotate the cartridge 55 about axis 14 thebottom end of the cartridge may have a protruding handle 190. Thedepicted handle comprises a short, elongated protrusion extending fromthe bottom of the cartridge 55 a distance sufficient to allow a person'sfingers to twist opposing ends of the protrusion 190. The depictedhandle is shown with an arbitrary curve resembling an “S” shape butother shapes can be used.

In the above depicted embodiments, the second fluid passage 32, 52, 76,78 preferably forms a fluid inlet for unfiltered fluid flowing into thefilter cartridge 55 while the first fluid passage 68, 66, 50 and 28forms a fluid outlet for the filtered fluid from the filter cartridge55. Depending on the configuration of the filter element and how wateris directed through the filter element the flow paths could reverse sothat the second fluid passage forms the outlet for filter water whilethe first fluid passage forms the inlet for unfiltered water. Thedetails of the fluid flow paths through the filter element 59 will thusvary with the particular cartridge 55.

Referring to FIGS. 7 and 14, a variation is shown with the barrel valvebody 36 omitted so that the filter cap 36 mates directly with themanifold 10. The barrel valve body 36 allows rotation of the valve body36 to shut off fluid flow to the filter cap 56 and filter cartridge 55.If the barrel valve body 36 is omitted a user actuates an externalshut-off to block flow through to the filter cap 36 and any cartridgeassociated with the filter cap. The parts have the same basicconstruction and function as described above, except the filter cap 56is sized to nest closely within the manifold 10. The first manifoldfitting 30 has the first manifold flow passage 28 passing through thefirst wall portion 18 of the manifold wall 12. The first manifold flowpassage 28 is in fluid communication with first filter cap flow channel66 located between seals 62 and 64 that encircle the first portion 58 ofthe filter cap and provide a seal against the facing interior sides ofthe first portion 18 of manifold 10. The first filter cap flow channel66 preferably encircles a substantial portion of the first portion 58 ofthe filter cap and opens into first filter cap openings 68 that extendthrough the walls of the first portion 58 of the filter cap to place thefirst channel 66 in fluid communication with the first internal fluidpassage 70 of the filter cap.

The second manifold fitting 34 has second manifold flow passage 28passing through the second wall portion 20 of the manifold wall 12. Thesecond manifold flow passage 32 is in fluid communication with secondfilter cap flow channel 6 which is located between upper and lower seals72, 74 that encircle the second portion 60 of the filter cap 556 andprovide a seal against the facing interior sides of the second portion20 of manifold 10. The second filter cap flow channel 76 preferablyencircles a substantial portion of the second portion 60 of the filtercap and is in fluid communication with the second filter cap openings 78that extend through the walls of the second portion 60 of the filter capto place second channel 76 in fluid communication with the secondinternal fluid passage 80 of the filter cap 56.

A top vent fitting 142 has a top manifold vent passage 142 that extendsthrough the fitting 142 and wall 12 or top 16 of the manifold 10 toplace the vent passage 142 in fluid communication with a top void volumewhich is formed mostly between the facing portions of the filter cap 56and manifold 10 isolated by first seal 62 located above the first filtercap flow channel 66. The top manifold vent volume includes the volumeformed by the facing surfaces of the top 16 of manifold 16 and top 86 offilter cap 56 and the facing surfaces above the seal 62 located on thefacing first side portions 18 of the manifold and 58 of the filter cap.

A middle void volume is formed between the second seal 64 and third seal72 and the facing outer surface of the filter cap 56 and the innersurface of the manifold 10 located between those seals 64, 72. Thefacing surfaces forming the middle vent valve preferably include part ofthe first wall portions 118, 58 and part of the second wall portions 20and 60 and part of the nesting shoulders 29 and 69 of the manifold andfilter cap, respectively. The middle manifold vent fitting 105 hasmiddle fluid passage 100 extending therethrough and through the wall ofthe manifold 10, preferably the first wall portion 18 so the middle ventpassage is in fluid communication with the middle void volume.

A lower or bottom void volume is formed between the fourth seal 74 andfifth seal 90 and the facing outer surface of the filter cap 56 and theinner surface of the manifold 10 located between those seals 74, 90. Thelower or bottom manifold vent fitting 158 has passageway 156 extendingtherethrough and through the wall 12 of the manifold 10, preferablyextending through the second portion 20 of the manifold wall or theflange 22, depending in part on the location of the fifth seal 90. Theseal 90 is shown as located between the second wall portions 20, 60. Thebottom manifold vent fitting is in fluid communication with the bottomvoid volume.

The filter cartridge 55 is used with the assembly of FIG. 14 pretty muchthe same as described regarding FIGS. 2, 11 and 12, as the filtercartridge mates with the same part, the filter cap 56. There is a slightdifference in the locking lug arrangement or other mechanism forretaining the filter cartridge 55 in place with the filter cap 56. Butsuch other locking lugs and retention mechanisms are known and notdescribed in detail. Thus a detailed description of the filter cartridge55 and the manifold 10 and filter cap 56 assembly of FIG. 14 are notprovided. The testing of the void volumes between the various seals 62,64, 72, 74 and 90 is also the same and not described in detail. There isone slight difference in that the flow passages through fittings 140,105 and 158 are shorter because the barrel valve body 36 is omitted, butthe testing is effectively the same steps, but with shorter passagesbecause the filter cap 56 seals directly to the surfaces of the manifold10, and the flow passages 48, 62 and 154 are omitted.

As described above, the seals 62, 64, 72 74 and 90 preferably compriseO-ring seals in grooves, but other seal types can be used with orwithout grooves, as is the case with the other seals described herein.The vent passages 142, 100, 156 are optional and if present allow one ormore of the void volumes to be placed in fluid communication with theenvironment or a device located outside the manifold 10. Thus the voidvolumes may be vented to atmosphere to help them remain dry; the voidvolumes may be monitored for moisture to indicate leaks; the voidvolumes may be filled with dry gas to ensure the void volumes are dryand thus not support bacteria growth or mold growth; the void volumesmay be pressurized to leak test the seals between the manifold 10 anfilter cap 56 which form the particular void volume in question. Thesesame tests or uses are applicable to the other void volumes and ventpassages descried herein, and other uses of the void volumes and ventpassages described herein may be used with the variation of FIG. 14.

The arrangement of FIG. 14 is especially useful for testing the seals ofa filter cap 56 before use. One or more of the vent fittings 140, 105,158 may be used to pressurize the void volume with which the ventfitting is associated and monitor the pressure for change in order toevaluate whether the seal or seals forming the vent valve are leaking.The void volumes are small and a pneumatic pressure can be appliedquickly and monitored accurately in order to rapidly test the sealsbefore approving them for sale. The use of dry gas avoids contaminationof the filter and avoids the need to dry the filter cap or filter. Thegas pressure may be monitored by pressurizing to a predeterminedpressure and monitoring the pressure change over a predetermined time,preferably a few seconds and more preferably less than 10 seconds andmore preferably fewer than 5 seconds. The monitoring may also includemonitoring the flow rate needed to maintain a desired pressure in thevoid volume, but this is less preferred. The equipment and process forpressuring volumes and monitoring the volumes for pressure changes orfor flow changes are well known and are not described in detail herein.

Referring to FIGS. 15-16, a method and apparatus for leak testing thefilter cartridges 10 is described. The leak test preferably uses a gasinstead of water or other liquid. In step 310, a source of pressurizedgas 330 is placed in fluid communication with the component to betested. Push-to-connect fittings are preferred. The source of gaspressure 300 is preferably a source of pressurized air such as an airtank or air compressor, but other cases may be used, including nitrogenand helium at a pressure higher than the test pressure discussed below.The connection with the filter component to be tested is preferablyachieved using one or more of the top, middle and bottom vent fittings140, 105, 158 respectively, as by clamping or otherwise connecting a gasline to the fitting to be used in the leak test. The tested filtercomponents may include the manifold 10 and filter cap 56 assembly as inFIG. 14, or the manifold 10, barrel valve 35, filter cap 56 and filterneck 134 assembly as in FIG. 7. Only one vent fitting and associatedflow paths and seals may be tested, or any two vent fittings andassociated flow paths and seals may be tested simultaneously, or allthree vent fitting and associated flow paths and seals may be testedsimultaneously. If only one vent fitting used it is preferably themiddle vent fitting 105 because the seals forming the void volumesaccessible by the middle vent fitting determine whether intermixingoccurs between the inlet and outlet flow paths through the filter.Intermixing is believed to be of significant concern from a potentialcontamination viewpoint.

The next leak testing step 312 pressurizes the void volumes associatedwith each vent fitting while controlling the pressure applied to thefilter cartridge components to a first pressure P1, preferably 30 psi,maximum for most current, household water filters. The pressure may beapplied by opening valve 332 and allowing gas to flow to the ventfittings 140, 105, 158 and the fluid passages and seal or sealsassociated with each of the vent fittings to form the associated voidvolumes. The pressure may be controlled by monitoring the pressure witha pressure transducer 334 such as a pressure gauge or other transducerand adjusting the pressure mechanically or electronically or otherwiseto regulate the pressure, as, for example by venting overpressure or bygradually increasing the pressure to the first pressure P1. The pressuremay be controlled by selecting or limiting the source of pressurized gas330 to provide a gas at a predetermined pressure, such as the firstpressure P1. The first pressure P1 may be the desired leak testpressure, which is preferably about 30 psi for household filtercartridges 10 and components such as manifold 10, barrel valve 36 andcap 56. The pressure applied during testing is preferably verified toensure proper operation of the equipment and testing.

The first pressure P1 may optionally be a higher, overpressure used toseat the seals associated with each void volume being tested and toimmediately open incipient leaks in those associated seals. The firstpressure P1 is preferably applied in a short time period of a fewseconds, preferably by opening an electronically actuated valve 332, asthrough a solenoid or other electronic control and shutting the valve soas to achieve the desired first pressure. Because the void volumesassociated with each vent fitting 140, 105, 158 are small the time tofill the void volumes is small and the time for the pressure to beachieved and stabilized sufficiently for accurate testing is small. Ifstep 312 is an over pressure test, then the next is to reduce thepressure in the tested components to the second, desired leak testpressure P2. As noted above, this test step is optional as P1 may be thesame as P2. The test pressure P2 is determined by the pressure monitor334 as described above, with the pressure being reduced by ventingpressure to atmosphere through a separate valve (not shown in FIG. 16)or by making valve 332 a three-way valve with an inlet from the gassource, an outlet to vent or atmosphere, and an outlet placed in fluidcommunication with the filter cartridge components to be tested.

The next leak testing step 314 is optional and allows manual activationof a start button to activate the pressure testing cycle.

The next leak testing step 316 is to monitor for leaks with sensor 336with the results being displayed on display 338, which may be a visibledisplay (e.g., red or green light) or an audio display (different soundsfor pass/fail) or both. Preferably the gas flow or gas pressure ismonitored by sensor 336 in electrical communication with detector unit337 that processes the sensor output to determine if a leak exists. Thesensor 336 and detector unit 337 may detect leaks various ways butpreferably detect changes in pressure or flow. The sensor 336 and thusthe detector unit 337 may be in communication with vent fittings 105,140, 158, or the fluid passages in communication with those various ventfittings, as described herein, as reflected by the solid lines in FIG.16. The sensor 336 and detector unit 337 could also be in communicationwith the fittings 30, 34 and the fluid passages associated therewith, asreflected by the dashed lines in FIG. 16. If sensor 336 is a flow sensorand there is no leak then the gas flow will be zero and the larger thegas flow the larger the leak. If the sensor 336 is a pressure sensor andthere is no leak then the pressure will remain constant, and the largerthe pressure drop the larger the leak. If sensor 336 is a pressuresensor it may be combined with pressure monitor 334 if properlypositioned in the test setup to monitor leaks. Because the void volumesare small, leaks will represent a relatively large change in the volumeand flow and thus be more quickly detected than if the entire filtercartridge were to be filled with gas or if the water flow passages wereto be filed with gas.

The leak test gas may be provided with a leak indicator to identify thelocation of the leak provided the leak indicator is not harmful tohumans and acceptable for use with the materials used in the filtercartridges. Mineral oil is fluorescent and in small quantities isbelieved to be suitable for use with the filter cartridges 10. Othersensors 336 for leak monitoring may be used, such as audio sensors todetect the sound of gas leaking past the seal under the applied pressureP1 or P2, and such audio sensors may be placed in the passages throughwhich water normally flows, such as inlet and outlet fittings 30, 34.Likewise the pressure or flow through the inlet and outlet fittings 30,34 and the fluid paths associated with those fittings may be monitoredbut that is not preferred because the volume of those associated fluidpaths is so large and changes in pressure and flow are more difficult todetect in the larger flow paths. The signals from the various types ofsensors 336 are preferably communicated to leak detector unit 337 whichevaluates the received signals to help determine if a leak exists andpreferably to provide some indication on the volume of fluid leaked orthe size of the leak. Various algorithms are known to correlate changesin flow or pressure or other aspects with the size of a leak or themagnitude of the leaked fluid, and are described herein.

The next leak testing step 318 is to determine if the filter cartridgecomponents being tested are acceptable. A pass-fail test is believedpreferable and the flow test or pressure test is believed preferable toimplement the pass-fail test. Depending on the application some leakagemay be acceptable but preferably the test criteria are to have no changein gas flow or gas pressure for a predetermined period of time. A shorttest time is believed suitable, such as a few seconds (e.g., from 1 to 5seconds), and even maintaining pressure for a fraction of a second isbelieved suitable for testing the various seals 42 associated with eachvoid volume.

The test results are preferably logged in step 322 to create a papertrail or electronic record that the part was tested, and the testresults. This recordation of the test results may reflect the date,time, test data, test criteria, pass, fail, or any combination of these.This step may occur after the step 320.

The next step in the leak testing is step 320 which releases thepressure and stops the test. This may be done by opening a pressurerelease valve between the valve 332 and the cartridge components beingleak tested or by venting at valve 332, or by disconnecting the gas linefrom the vent fittings 105, 140, 158. This step is done whether thetested filter component passes or fails the leak test.

If the filter component has passed the leak test then next step 324 inthe leak testing sequence is to determine if all of the desired ventfittings and associated void volumes and seals have been tested, and ifso, to route the good units to location for further processing. If thetest sequence tested the void volumes and seals associated with only onevent fitting, then the sequence may be repeated by connecting the gassource to a different vent fitting and the sequence repeated until allvent fittings to be tested are tested for leaks. If all of the ventfittings to be tested were connected in the first step 310 or by cyclingthe filter component through the leak test sequence for different ventfittings and associated void volumes and seals then the testing may alsobe completed. If a single test is being performed then step 324 simplysends the good, pressure tested unit for further processing, such aslabeling and packaging.

If the filter component has failed the leak test at step 318, then afterthe pressure is released and testing stopped in Step 320, the cartridgemay be disconnected in step 326 from the gas lines and removed from thetest setup for subsequent disposition. The tested component may bediscarded, or recombined with other components and retested as discussedlater. Advantageously, whether the filter component passes or fails thepressure is released in step 320 and the part is preferably disconnectedfrom the gas lines in step 326. Thus, these steps may be combined withthe same sequence of steps as if the filter component passed the testbut with the passed components being separated from the failedcomponents after the gas lines are disconnected. Further retesting ispossible, as described later.

The final step 326 is to remove the filter cartridge components beingtested from the test location and sort them according to the pass/failcriteria. The test sequence is then restarted by connecting thecomponents of the next filter cartridge to be tested to the gas sourceas in step 310. Note that if the filter cap was being leak tested in atest manifold then the filter cap 56 could be discarded if it failed theleak test step 318. But if a combination of a manifold 10 and filter cap56 were leak tested and a leak was indicated it is not necessarily knownif the leak was attributable to defects in the manifold 10 or the filtercap 56. Both parts may be discarded if a leak is found, or one or bothparts may be combined with a different part and retested on theassumption that the defective part will cause the combination of themanifold and filter cap to fail a second time. But that retestingrequires tracking parts that have failed once and the cost of retestingand errors in tracking the retested parts must be balanced against thecost of the parts to determine if retesting is economically practical.The same applies to leak testing combined assemblies of a manifold 10,barrel valve 36, filter cap 56 and cartridge neck 134, as one or morecomponents may cause or contribute to a detected leak.

Still referring to FIG. 15, further retesting of failed parts may beoptionally performed. While a failed part may simply be recycled throughanother pressure test, it is preferred that the failed part bedisconnected in step 326, and then in step 328 the connections of thetest equipment and the mating connections on the part being tested areinspected to see if they are the cause of unsatisfactory testing. Thepart should also be checked to see if there are indications of damage orreasons for failing the test. If the part appears suitable onre-inspection, the part is then reconnected to the tester as in step310. As an alternative, the connections with the test equipment may bechecked without disconnecting some or all of the gas lines with the partthen recommencing testing at step 312.

The reconnected part is then retested through steps 312, 314, 316 and318. Advantageously the test sequence keeps track of retested parts sothat if there is a second failure, then after the pressure is releasedand the test stopped, in step 329 the part is routed to variouslocations for further disposition. Such further disposition could be areject bin, scrap, recycling, QC inspection, or rebuilding. Instead ofhaving software track retested parts, an operator may manually trackretested parts. The above testing sequence and variations as in FIG. 15is preferably automated, but may use manual operations.

It is preferred to have each part tested individually in an outertesting device that simulates the cartridge part into which the testedpart fits or mates or nests during use with an inner testing device thatsimulates the cartridge part which is inserted into the tested partbeing optionally used for further accuracy of simulated testing. Thus, abarrel valve 36 to be tested may be inserted into an outer test manifoldand have an inner test filter cap optionally inserted into the barrelvalve 36 to form void volumes that test only the seals 42, 50, 44, 54and 90 between the barrel valve 36 and the manifold 10. Likewise, filtercap 56 to be tested may be inserted into an outer test barrel valve 36(and optionally a test manifold 10) with an inner test filter cartridgeneck 134 optionally inserted into the tested filter cap 56 in order totest only the seals 62, 64, 72, 74 and 90 between the filter cap and thebarrel valve.

A preferred test setup uses a RICO test device as shown in FIG. 17. Thisuses the same basic test sequence of FIG. 15. A source of pressurizedgas 330 provides gas to three-way valve 332 which vents gas to releasedownstream pressure. The valve 332 provides gas to two different linesthat may be placed in fluid communication with the vent fittings 105,140, 158 on two different filter cartridge components, or that may beplaced in fluid communication with two different vent fittings 105, 140,158 on the same filter cartridge component. This test setup isadvantageous when only two vent fittings are to be tested or when thefilter cartridge components have only two vent fittings.

The test cycle begins by connecting each of two gas lines to the samevent fitting 105, 140, 158 on two different filter cartridge componentsto be tested (e.g., 10, 36, 56, 134), or on any combination of twodifferent vent fittings of the same filter cartridge component. Theseoptions are represented by the arrows in FIG. 17. The solid linesreflect preferred connections with the vent fitting 105, 140, 158 orfluid passages associated therewith, with the broken lines reflectingless preferred connections with the first and second fittings 30, 34 andthe fluid passages associated therewith. Any combination of thesefitting or their associated fluid passages may be tested. Then the valve332 is opened to pressurize both gas lines to the two different ventfittings and associated void volumes and the seals forming the voidvolumes. The pressure monitor 334 can be used to regulate the pressureto P1 if an overpressure is used, or to achieve test pressure P2, asdesired, with the valve 332 venting to reduce an overpressure P1 to thedesired test level P2. When the test pressure P2 is achieved anisolation valve 333 on each gas line closes to lock in the test pressureP2. The isolation valves 333 are open during the overpressure testing P1or the filling of the gas lines and void volumes. With the isolationvalves 333 closed a fixed volume is defined and the pressure or flow ismonitored for a test time interval. During the test interval the onlyflow path between the two gas lines is through flow sensor 336. If thevoid volumes and associated seals do not leak, then there is no gastransfer through the flow sensor 336 and detector 337, even if bothtested components are deforming at the same rate due to material creepor if the pressure is changing in both components due to heat transfer.Compensation for these deformation or heat transfer errors is inherentlyachieved because two identical components and the same void volumes arebeing tested simultaneously and the flow sensor compares two testedcomponents with identical creep and thermal characteristics. Thatremoves the need to delay testing to wait for the tested components tostabilize in temperature or to expand under the test pressure.

If one tested component leaks then gas flows from the non-leakingcomponent to the leaking component and the flow is detected by flowsensor 336 and detector 337 and optionally displayed on a suitabledisplay device 338 as described above, activated by detector unit 337. Acomparison circuit may be provided to compare an electronic valuerepresentative of the pressure or flow detected by sensors 334, 336 witha reference value with the comparison circuit sending a signal toactivate an audible or visual signal to display 338, or both dependingon whether the change in pressure or flow, or the lack of change inpressure or flow indicates a pass or fail.

If the tested component of the filter cartridge passes then the pressureis released by opening isolation valves 333 and venting through the ventof three-way valve 332. Alternatively, the isolation valves 333 may bethree way valves that also vent to atmosphere. Additionally, the ventfittings 105, 140, 158 may have a quick disconnect fitting on the end,such as a barb configured to quickly engage with a pneumatic couplingand release of the gas line from the vent fittings could release thepressure. The same applies to the prior embodiment of FIGS. 15, 16.Depending on whether all desired filter components, vent fittings andassociated void volumes have been tested the gas lines may bereconnected to different vent fittings for further testing, or thefilter component may be removed for further use. If the tested filtercomponent failed, then it may be discarded or otherwise handled asdescribed herein.

Referring to FIG. 18, a test arrangement is shown using a source ofpressurized gas 330 which provides gas to a three way control valve 332.The valve 332 is opened to provide pressurized gas to three differentgas lines each connected to a different one of vent fittings 105, 140,158, with pressure monitored by pressure sensor 336 and detector 337.The solid lines reflect preferred connections with the vent fitting 105,140, 158 or fluid passages associated therewith, with the broken linesreflecting less preferred connections with the first and second fittings30, 34 and the fluid passages associated therewith. Any combination ofthree (or more) these fitting or their associated fluid passages may betested, with a dedicated isolation valve 333 and sensor 336 associatedtherewith. The pressure sensor 336 may be configured to provide a signalthat closes valve 332 or isolation valves 333 when the desiredoverpressure pressure P1 or desired test pressure P2 is reached in thegas lines. As desired, a separate pressure sensor 336 may be providedwith each gas line and isolation valve 333. When the desired pressure isreached the isolation valve 333 is closed and sensor 336 and/or detectorunit 337 checks for leaks. The sensor 336 and detector unit 337 is shownas connected to the gas lines to monitor flow (or optionally to monitorpressure), with each sensor 336 connected to a common display 338.Separate displays 338 for each sensor 336 or separate detectors 337could be used. The sensor 336 could also be located inside the first orsecond fittings 30, 34, respectively as described above, or it couldcomprise other sensor types. This arrangement allows testing of threevent fittings and associated void volumes and seals at the same time,using the test sequence as generally described regarding FIGS. 15 and16.

The middle vent fitting 105 can provide fluid access to leak test theseals that separate the inlet and out flow paths through the filtercartridge 10. As seen in FIG. 7, the middle vent passageway 100 inmiddle vent fitting 105 provides access to seals 104, 106 between theoutside of the barrel valve 36 and the inside of the manifold 10 whichseparate the first flow passages 28, 66 from the second flow passages32, 52 through the manifold and barrel valve. The middle vent passageway100 in middle vent fitting 105 also provides access to seals 64 and 72which separate the first flow passages 28, 48, 68 from the second flowpassages 32, 52, 76 through the manifold 10 and barrel valve 56 to thefilter cap 56. If the vent passage 136 extends through the wall of thefilter cap 56 then the middle vent passage also allows access to theseals 130, 132 on the neck 134 of the filter cartridge 55. Thus, bytesting the middle vent passage 100, 102, 136, preferably via middlevent fitting 105, the seals separating the first and second flowpassages can be tested to see if any seals leak and allow intermixing ofwater flowing in the two flow passages.

The test equipment described above preferably connects to the ventfittings 105, 140, 158 (or first and second fittings 30, 34). But thefluid connections with the test gas or test fluid could be provided withthe vent passages themselves rather than the test fittings. Thus, thetop vent passage through one or more of passages 142, 144 could be usedto test one or both of seals 42, 62. The middle vent passage through oneor more of passages 100, 102, 136 could be used to test two or more ofseals 64, 72, 130, 132 encircling the filter cap 56 and cartridge neck134, as well as to also test the seals 104, 106 encircling the barrelvalve and interposed between the manifold 10 and barrel valve 36.Likewise, the lower or bottom vent passage through one or more ofpassages 156, 154 may be used to test one or both of seals 74, 90encircling the filter cap and barrel valve, respectively, as well as toseals 44, 152 between the barrel valve 36 and manifold 10.

While the various vent passages allow testing the void volumes and theseals forming those void volumes to ensure the seals are likely toprevent leaks, the vent passages have other advantages. In arefrigerated or cooled environment, one or more of the vent passages mayallow air to be circulated through the void volume associated with theselected vent passage. Circulation of even ambient air through the topvent passage may prevent freezing in many applications, in addition tokeeping the vent passage and void volumes dry to inhibit bacteriagrowth. Circulation of heated air, as achieved by passing air by anelectrical resistant heating element powered by the appliance into whichthe filter cartridge is placed, can help avoid freezing of water aroundthe neck of a filter cartridge at even colder temperatures than ambientair. Thus, the vent passages can help leak check the filter cartridgeand barrel valve, as well as help those parts from freezing if theappliance temperature or water temperature drops too low.

The above description preferably uses generally cylindrical mating partsbecause the generally cylindrical surfaces may be made with accuracy andinexpensively, and circular seals provide good seal capability at a lowprice. As shown in the figures, the upper cylindrical portion ispreferably smaller in diameter than the lower portion, with a laterallyextending, stepped shoulders 29, 69 on the barrel valve and filter cap,respectively. The use of a smaller diameter on the distal end of theseparts makes insertion easier. If the first and second portions are thesame diameter then the first and second seals on the barrel valve andfilter cap must pass through the entire length of the manifold andbarrel valve, respectively, and the sliding that increased length willincrease the friction, requiring more insertion force. A larger diameteron the second portion of these parts requires a shorter insertion lengthon the first, smaller diameter portion and the first and second seals.Also, if the first and second portions are the same diameter then theO-ring seals pass the various inlets, outlets and vent passages, each ofwhich has an edge that may catch, cut and abrade an O-ring seal as itpasses by, degrading the performance of the seals. Thus, while havingthe first and second portions the same diameter is possible and offersthe advantage of allowing common sized seals to be used on the first,second, third and fourth seals, it is preferred to have the first andsecond portions of different diameter, with the first and second sealshaving the same diameter which is small than the third and fourth seals,which also preferably have the same diameter.

Where parts have to be rotated relative to each other about a commonaxis the generally cylindrical shape with aligned longitudinal axes isvery desirable. But the filter cartridge 55 and its neck 134 do not haveto rotate relative to the filter cap 56. The filter cap 56 does notrotate relative to barrel valve 36 as those parts are interlocked bychannel 162 and channel tab 168 and rotate together within manifold 10to align flow paths and optionally to align vent paths. Because theabove identified parts do rotate relative to each other, they may have anon-circular shape. In particular, the filter neck 134, filter cap andinterior of barrel valve 36 may have a generally oval configuration asgenerally shown in U.S. Pat. No. 8,591,736, the complete contents ofwhich are herein incorporated herein by reference, or otherconfigurations disclosed in that patent.

Referring to FIGS. 19-21 the lateral filter cap 56′ is shown extendinglaterally from the filter cartridge 55′ along cap axis 14′, away fromthe longitudinal axis 14 of the filter cartridge and preferably in aplane orthogonal to the longitudinal axis of the filter. The vastmajority of the parts of the lateral filter cap 56′ are the same and adetailed description of those parts is not repeated while the same partnumbers are used to identify those same functioning parts. Because thelateral filter cap 56′ extends laterally, the connections between theaxially aligned filter housing 57 and filter 59 are altered. The lateralfilter cap 56′ could extend laterally from a sidewall of the filterhousing 57, but that extends the filter cap a large lateral distancebeyond the general peripheral shape of the filter housing 57.Preferably, the distal end of the filter cartridge 55′ has an offsetmount from which the filter cap 56′ extends so that the filter cap is inthe general cylindrical volume of the filter body extending alonglongitudinal axis 14.

In the depicted embodiment, one side of the filter housing 59 extendsupward along longitudinal axis 14 to form a closed upper or distal end400 of the filter housing. A cylindrical shape could be used but a domedor half domed shape is preferred. The distal end 400 preferably has anaxial face 402 aligned with the filter cartridge's longitudinal axis 14and a lateral face 404 aligned with the lateral axis 14′ and extendinglaterally from the bottom of the axial face 402. The lateral filter cap56′ also extends laterally along lateral axis 14′ and preferablyparallel with the lateral face 404. The closed end 86 of the lateralfilter cap 56′ is adjacent a curved plane extending along a periphery ofthe generally cylindrical body 57 enclosing the filter 59. As used herethe term “adjacent” means within a distance of about ⅓ the length of thelateral offset cap along lateral axis 14′ beyond or outward of theperiphery of the housing body 57.

The lateral face 404, vertical face 402 and distal end 400 enclose thedistal end of the filter cartridge 55′. The faces 402, 404 arepreferably generally flat and perpendicular to each other. The filtercap 56′ extends laterally from the axial face 402 and preferablyperpendicular to that face, but the faces 402, 404 could be of diverseshape. The distal end 400, axial face 402 and lateral face 404 arepreferably molded simultaneously with the housing 57, with appropriatedraw angles being provided on the interior and exterior faces of theparts to make molding easier.

The lateral filter cap 56′ is offset from the lateral face 404 adistance sufficient to allow the lateral filter cap to mate with aconforming manifold head 10′ as described later. To maintain the flowchannels 66, 76 of the filter cap in fluid communication with the sameparts of the filter 59, the filter cap 56′ is advantageously molded as aseparate part and then connected to the distal end 400 filter cartridgehousing 57, preferably by spin welding the cap to the distal end 400, tothe axial face 402, or to parts contained within the distal end of thefilter cartridge. The filter cap 56′ may be fastened to the adjacentportion of the filter housing 57 near the location of the lateral face404 as shown in earlier embodiments. But alternatively, the housing 57may be injection molded with the distal end 400 and axial face 402, withthe filter 47 inserted and an end cap 405 (FIG. 20) put on the end toenclose the filter and form the fluid tight cartridge 55′.Advantageously, parts 134′, 416, 418 (described later) may be attachedto the filter 59 when it is inserted into and enclosed in the filterhousing 57 by the end cap 405. The end cap 405 may be spun welded to thehousing 57 or fastened by other fluid tight means.

As best seen in FIG. 21, the first internal fluid passage 70 of thelateral filter cap 56′ is formed as a first, generally cylindrical,inner tube 406 having an interior diameter that is slightly larger atits base and slightly smaller at its laterally outermost end. The firsttubular portion 406 forms the distal, first portion 58 of the filter cap56′. The first filter cap openings 68 may extend through this first tube406 to place the interior passage 70 in fluid communication with thepassages 68 and flow channel 66. The flow channel 66 and seal channels62 a, 64 a are formed on the outer surface of the outermost end of thisinner tube 406 at the first portion 56′ of the lateral filter cap. Anannular recess 408 is formed in the wall of the first tube 406 andextends from the base of that tube toward the outer end of that firsttube. The annular recess 408 extends along the second portion 60′ of thelateral filter cap on which are located the second flow channel 76 andseal grooves 72 a, 74 a. The annular recess 408 forms a flow channel influid communication with the second flow channel 76, and preferablyencircles the first internal fluid passage 70. The annular recess 408has a closed end adjacent the shoulder between the first and secondportions 58, 60′ of the filter cap with the opposing end of the recess408 opening toward the base to form a portion of the identified flowchannel. Thus, the proximal end of the annular recess 408 adjacent thefilter cap 56′ near the juncture with the axial wall 402 is formed bytwo concentric tubes, inner tube 406 and outer tube 409. The outer wallof tube 406 and the inner wall of tube 409 face each other and form therecess 408. The tubes 406, 409 slightly diverge from each other as theyapproach the axial face 402 so that the recess 408 is slightly larger indiameter adjacent the axial face 402. The slightly divergent walls helpmold the recess 408 and allow a plug to form the recess 408 and bewithdrawn from the open end of the lateral filter cap 56′ before it isfastened to the filter cartridge. The tubes 406, 409 are generallyparallel to each other and extend along filter cap axis 14′, with theouter tube 409 being concentric with and encircling the inner tube 406.Both tubes are centered about filter cap axis 14′. One tube 406, 409extends further than the other tube along filter cap axis 14′, withinner tube 406 extending further as shown in FIG. 21. The second filtercap portion 60′ is on the outer wall of the outer tube 409. The outertube 409 ends adjacent the juncture of the first and second filter capportions 58, 60′.

A position stop 410 is located on the outer tube 409 adjacent the baseof the lateral filter cap 56′ and preferably has wrenching surfaces onthe stop, which wrenching surfaces extend outward relative to thelateral filter cap axis 14′. A groove 412 encircling the second filtercap portion 60′ and the lateral filter cap 56′ is located next to butoutward of the position stop 410, and is formed on the outer surface ofouter tube 409. The base of the second filter cap portion 60′ and outerwall 209 extends beyond the position stop 410 and the inner passage 70formed by the inside of inner tube 406 extends beyond the end of thesecond portion 60′ and outer tube 409. The axial face 402 has an openinglarge enough to allow the outer tube 409 to fit through the opening.Preferably the axial face 402 has a circular hole to allow insertion ofthe base of the second portion 60′ formed on outer tube 409, which ispreferably cylindrical along the inserting portion. The axial face 402and outer tube 409 of the filter cap's base portion 60′ may be fastenedtogether with threads, adhesives, etc. But preferably the opening in theaxial face 402 and the outer tube 409 are sized so they can be connectedby spin welding along first connecting surface 412, with the stop 410limiting the distance that the lateral filter cap 56′ and outer tube 409are inserted into the opening in the axial face 402 and into the distalend 400 of the filter housing. The wrenching surfaces on the positionstop 410 may be used for the rotation to achieve the spin welding. Thedepicted embodiment has a slight boss on the outside of the opening inthe axial face 402 and a stepped opening through the wall forming theopening through which the second portion 60′ is inserted for spinwelding. Advantageously, the end of the second portion 60′ is flush withthe inner surface of the axial face 402 when the lateral filter cap 56′is connected to the axial face.

Still referring to FIG. 21, the filter 59 has a tubular neck 134′ thatis laterally offset to accommodate the lateral orientation of thelateral filter cap 56′. The offset tubular neck 134′ extends upward froman upper end cap 416 which fits over and mates either directly with thefilter body 59 or mates with an end fitting 418 of the end cap. The endfitting 418 blocks the upper end of the cylindrical filter body 59 toforce water to flow radially through the filter body. The upper end cap416 creates a space so the water from the center of the filter body canflow laterally to the offset neck 134′. The offset of the neck 134′ willvary as needed to create a fluid passage to the appropriate fluidpassage of the lateral nozzle 56′. The offset neck 134′ extends parallelto but offset from filter axis 14 a distance sufficient to connect tothe internal end of the first internal fluid passage 70 of the filtercap 56′. The inner tube 406 enclosing that first fluid passage 70extends laterally beyond the end of the tube 409 forming the outerportion of the second filter cap portion 60′. The distal end of theoffset neck 134′ has an opening, preferably circular, into which themating end of the inner tube 406 fits. Advantageously, the inner tubeportion 406 is spun welded to the opening in the offset neck 134′ toform a second connecting surface 420. Preferably, connections 412, 420are formed simultaneously by spin welding lateral filter cap 56′.Advantageously, the mating portions of the end of tube 406 and the holein offset neck 134′ are sized and configured to form a fluid tightconnection, preferably by spin welding. Advantageously, the end of tube406 is flush with the interior surface of the offset neck 134′.

Referring to FIG. 21, a first fluid flow passage is formed through thefirst flow channel 66, first filter cap openings 68, first internalfluid passage 70, offset neck 134′, filter end cap 416, end fitting 418and filter body 59. A second fluid flow passage is formed through thesecond flow channel 76, second filter cap openings 78, annular recess408 (which corresponds to the second internal fluid passage 80), and thedistal end 400 and face 402. The interior of the distal end 400 andaxial face 402 is spaced apart from the components forming the first andsecond flow passages, with standoffs 422 providing strength and bracingof parts as needed while allowing fluid flow around the standoffs asneeded. Advantageously the axial wall 404 is located at or slightlyoffset away from the longitudinal axis 14 of the filter cartridge sothat the abutting connection between the lateral manifold 430 and thelateral filter cartridge 56 occurs at about that axis 14. While thefilter cap 56 in FIGS. 1-14 has a fairly uniform wall thickness with astepped diameter between the first and second filter cap portions 58,60′, the lateral filter cap 56′ of FIG. 21 has a thicker wall on thesecond filter cap portion 60′ and is effectively formed by two tubularportion 406, 409 that form annular recess 408 between them to form partof the flow path through fluid passages 76 in the second portion 60′.

The lateral filter cap 56′ thus uses the same basic filter cap 56 ofFIGS. 1-18, but the second portion 60 is formed of two concentric tubes406, 409 in order to create annular flow channel 408 which is in fluidcommunication with the outside of the cylindrical filter element 59 inthe depicted embodiment. To accommodate the separate flow channels 70,408, the base of the outer tube 409 is sealingly connected to the axialface 402 while the base of the inner tube 406 is sealingly connected tothe offset neck 134′. The flow path 70 formed inside of the inner tube406 extends toward the end 86 of the filter cap 56′ and into the firstportion 58 of the end cap, while the annular recess 408 ends adjacentthe juncture of the first and second portions 58, 60 of the end cap. Thedepicted juncture has an outwardly extending shoulder between the firstand second portions 58, 60, but the outer periphery of the filter cap56′ could be generally the same diameter with an inward extendingshoulder so the internal diameter of passage 70 in the first portion 58is smaller in diameter than the internal diameter of that same passagein the second portion 60. In short, the walls of the first portion 58could be thicker than the combined walls 406, 409 (and space 408)extending along the second portion 60.

The filter cartridges 55′ with laterally offset neck 56′ may be used inmanifold filter assemblies. The previously described bayonet lock may beused to connect each filter cartridge to a corresponding manifold, butthat may require rotating each cartridge a quarter turn or 90° and thatmay in turn require sequential removal and re-installation of thecartridges if they are close enough together that an interior cartridgecannot be rotated without hitting an adjacent cartridge.

Referring to FIGS. 22-25 and 27, a locking connection to a laterallyinsertable manifold head 430 is disclosed. A plurality of filtercartridges 55′ with lateral necks 56 a may be connected in series orparallel, with parallel connection shown in FIG. 22. The manifold heads430 a, 403 b, 430 c are each held in a mounting bracket 432 a, 432 b,432 c, respectively. The brackets 432 may have various configurations tohold the manifold heads 430 with the configuration varying according tothe surface to which the manifold heads are connected. For connecting toa vertical wall the brackets 432 are shown as comprising L brackets witha vertical back portion 434, a horizontal top portion 436 and aninclined lip 438 for stiffness. One or both of the backs 434 and tops436 may be offset at the ends in order to nest with and interlock withabutting brackets as shown in FIG. 25. The brackets could be C shaped orhave other shapes as needed to provide support for the filter cartridgesor to conform to local building codes. Preformed holes may be providedfor fasteners to connect the brackets to supporting building structures.The brackets are typically made of metal but could be of variousmaterials. The depicted brackets 430 have a notch or cutout 439 in oneend of each lip 438 to accommodate a lock release as discussed later.The manifolds 430 are oriented so the manifold mounting flange 22 isfacing away from the vertical wall 434 of the mounting bracket 432, toreceive the filter cap 56′. The manifolds 430 are connected to therackets 432 by threaded fasteners, although other connections may beused.

The filter cartridges 55′ connect to first and second tubes 440, 442, inparallel, with one tube carrying unfiltered water and the other tubecarrying filtered water. Tubes having a diameter of about ½ inch andmade of suitable water compatible materials are believed suitable. Themanifolds 430 are as generally described regarding manifolds 10′ and thedescription of corresponding parts with corresponding part numbers isnot repeated. The main structural differences between manifolds 430 frommanifolds 10′ are the use of a releasable lock, the fluid connectionwith the tubes 440, 442, and a kick-out mechanism. The releasable lockmay be replaced with the mounting tabs described in the axially alignedcap 56 of FIGS. 1-18, but that is not preferred.

Referring especially to FIGS. 23, 24 and 27, a locking mechanism isprovided to releasably connect the filter cartridge to the manifold ormounting bracket. Advantageously, a latch 446 on one of the cartridge55′, manifold 430, tubes 440, 442 or bracket 432 is resiliently urgedinto engagement with a mating part on the other of the bracket 432,manifold 430, tubes 440, 442 or cartridge 55′. Advantageously the latch446 moves inward or outward relative to lateral axis 14′ of the lateralcap 56′ to releasably engage the mating part of the latching mechanism.In the depicted embodiment the resilient latch 446 comprises a ringencircling the lateral cap 56′ and located to be resiliently urged intoa portion of an annular groove 448 in the lateral filter cap 56. Theannular groove 468 is advantageously adjacent the position stop 410 andaxial wall 402 to provide a sturdy connection with the filter cartridge55′. The ring-shaped latch 446 is enclosed in an annular recess 450 ofthe manifold 430, preferably located adjacent the manifold mountingflange 22 (FIG. 23). The annular recess 450 encircles the passagethrough which the lateral filter cap 56′ passes when inserted into thelaterally orientated manifold 430. In the depicted embodiment the tube442 extends through part of the manifold and the recess 450 so a portionof the recess is in the tube 442 or the brackets supporting the tube442. A spring resiliently urges the ring shaped latch 446 to extend intoand partially block the passage into the manifold 430 (FIG. 23). As bestseen in FIGS. 24 and 27, the spring may comprise a resilient latch 446having a portion of the encircling ring shape split into an inner andouter segment so the outer segment may be resiliently deformed towardthe inner to allow the filter cap 56′ to pass the inner segment whilethe deformed outer segment acts like a deformed spring to urge the innersegment into the latching recess 448 (FIG. 19). Thus, the split segmentof the encircling ring shaped latch 446 acts as a resilient member tourge the latch into the locking position. A split segment extendingalong an arc of about 270° is believed suitable. The annular space 450in the manifold is large enough to accommodate the latching movement ofthe latching ring 446. A latch tab 452 is connected to the latching ring446. The depicted tab 452 extends outward through an opening in thesidewall of the manifold best seen in FIG. 23.

During use, the lateral filter cap 56′ is inserted laterally though theopening in the bottom of the lateral manifold 430 adjacent flange 11until the cap is seated in the manifold, at which time the latching ring446 is resiliently urged into the annular recess or groove 448 in thelateral filter cap 56′ and extending part way into the opening of thelateral manifold 430 (FIG. 23). If the filter cap 56′ is moved alonglateral axis 14′ a portion of the latch 446 will abut the sides or edgesof recesses 448, 450 to restrain relative movement of the cap 56′ andmanifold 430. The latch tab 452 may be pushed inward to move the ringshaped latch 446 into the annular recess 450 in the manifold to allowthe lateral filer cap 56′ to be withdrawn from the lateral manifold.

Advantageously, the fit between the latch 446 and recesses 448, 450 issnug enough that the lateral filter cap 56′ does not move much relativeto the lateral manifold 430. The latch tab 452 may be at variousorientations, with notches or cut-outs 329 allowing passage of the latchtab 452, as needed. Having the latch tab orientated at an angle of about30-6-degrees from the vertical is believed desirable to make it easierto activate the latch tab while manipulating the filter cartridge 55′.

Referring to FIGS. 24-27 and especially FIGS. 24 and 25, the first tube440 advantageously passes through the lateral manifold 430 so a portionof that the first tube is in fluid communication with first fluidpassage 66 of the lateral filter cap 56′ during use, preferably throughopenings 458 in the first tube 440. Advantageously the first tube 440 islocated above the lateral axis 14′ and above the first portion 18 (FIG.26) of the filter cap 56′. Fluid thus flows through filter neck 134′ andpassages 70, 68 66 and 458 to reach the first tube 440. The openings 458are shown as two adjacent openings with a divider so that the O-ringseals 62 b, 64 b the do not enter the openings 458 and cut, abrade orotherwise damage the seals when the filter cap 56′ is inserted into themanifold. The openings 458 correspond to the first manifold flow passage28 (FIG. 1). Depending on the flow through filter cartridge 55′, thatflow path could carry unfiltered or filtered water. In the depictedembodiment it preferably carries filtered water.

Referring to FIGS. 24-26 and especially FIGS. 24 and 26, the second tube442 advantageously passes through the lateral manifold 430 so a portionof that the second tube is in fluid communication with second fluidpassage 76 of the lateral filter cap 56′ during use, preferably throughopenings 456 in the second tube 442. The openings 456 are shown as twoadjacent openings with a divider so that the O-ring seals 72 b, 74 b thedo not enter the openings 456 and cut, abrade or otherwise damage theseals when the filter cap 56′ is inserted into the manifold. Theopenings 456 correspond to the second manifold flow passage 32 (FIG. 1).Advantageously the second tube 442 is located below the lateral axis 14′and below the second portion 20 (FIG. 26) of the manifold.Advantageously the first tube 440 is located above the lateral axis 14′and above the first portion 58 of the filter cap 56′. Fluid thus flowsaround the outside of the filter neck 134′ and into the annular recess408, through flow channel 76, and passages 78, 456 to reach the secondtube 442. Depending on the flow through filter cartridge 55′, that fluidpath could carry unfiltered or filtered water. In the depictedembodiment that is preferably unfiltered water.

As best seen in FIG. 25, the tubes 440, 442 may be made ofinterconnected segments, with some segments configure to pass throughthe lateral manifolds 430 and other segments configured to connect themanifold segments of the tubes. Advantageously, various connectors 460(FIG. 23) such as fasteners, brackets, clips or claims, preferablyC-clips, may connect the tubes to the brackets 432. If the thickness ofthe segments of the tubes 440, 442 permit, the connectors 460 may matewith corresponding recesses 461 (FIG. 26) in the tubes.

Referring to FIG. 24, the lateral filter cap 56′ is inserted laterally,preferably horizontally into the manifold 430. Upon release of the latch446 by pressing tab 452, the filter cartridge 55′ may be moved laterallyaway from the manifold to disengage the cap 56′ from the manifold 430.Because the fluid enters the flow channels 66, 76 radially to the axis14, 14′ along which the filter cap 56, 56′ extends there is little or noaxial pressure tending to push the cartridge out of the manifold.Advantageously, a resilient member 462 urges the filter cartridge awayfrom the manifold to avoid any vacuum lock as may arise from the closelymating parts sealed by several O-ring seals. The resilient member 462may urge any portion of the lateral filter cap 56′ or cartridge 55′ awayfrom the manifold or bracket. Thus, springs or other resilient membersmay be located between the manifold 430 and filter cap 56′, between thebracket 430 a n filter cap 56′, between the bracket and filter cartridge55′. In the depicted embodiment the resilient member 462 comprises aspring urging a disk 464 toward the end 86 of the lateral filter cap56′. The disk 464 has a cylindrical post 466 passing through a hole inan end wall of the manifold 430 so the spring pushes the disk and postagainst the end of the filter cap to resiliently urge the filter cap 56′and filter cartridge 55′ out of the manifold 430.

The above description of the lateral filter cap 56′ and cartridge isdescribed as having the cartridge vertical, but that need not be so. Thecartridge may be in any orientation, including vertically up, verticallydown, horizontal, or at any angle between those positions. The abovedescription of the lateral filter cap 56′ and lateral manifold 430 didnot discuss the location of the vent passages 142, 105 and 156 to applygases to or check moisture in the end portion defined by seal 62, orbetween adjacent seals 64, 72, or beyond seal 74 and the base of thefilter cap. Those aspects are described above and that descriptionapplies to the embodiment of FIGS. 19-24.

The lateral filter cartridge 55″ provides a lateral connection with afilter manifold head 430 having a flow inlet and a flow outlet, whichcould be through the channels 28, 32, depending on the particular filterand manifold design. The filter element 59 is in fluid communicationwith a filter inlet and filter outlet so that liquid from the manifoldflow inlet passes through the filter inlet and filter and out themanifold outlet. The lateral filter cap for the lateral filter cartridgeincludes a first generally cylindrical portion 58 with a first fluidpassageway 68 extending inward toward a longitudinal axis 14′ of thelateral filter cap 56′. The lateral filter cap axis 14′ is in a planeorthogonal to the filter cartridge axis 14. The first fluid passageway70 forms one of the inlet or outlet of the filter cartridge depending onthe particular manifold and filter construction. The lateral filter cap56′ has a second generally cylindrical portion 60 with a second fluidpassageway 78 extending inward toward the lateral filter cap axis 14′and forming the other of the inlet or outlet of the lateral filtercartridge. The lateral filter cap 56′ has closed end 86 with the firstgenerally cylindrical portion 58 further from the filter axis 14 thanthe second generally cylindrical portion 60. The first and secondgenerally cylindrical portions 58, 60 have respective first and secondouter diameters with the first outer diameter being smaller than thesecond outer diameter. The filter cap has a first internal cavity 70formed in part by the first generally cylindrical portion 58 and influid communication with the first fluid passageway 68 and extendingalong the lateral filter cap longitudinal axis 14′ along a length of thefirst and second generally cylindrical portions 58, 60 of the lateralfilter cap 56′. A second internal cavity extends along the second,generally cylindrical portion 60 of the lateral filter cap 56′ andincludes annular recess 408 encircling the first internal cavity 70 andextending along the filter cap longitudinal axis 14′. The lateral filtercap 56′ connects to the distal end of the filter housing 57 enclosingthe filter 59, preferably connecting along axial face 402.

First and second seal members 62 b, 64 b encircle the outside of thefirst generally cylindrical portion 58 on opposing sides of the firstfluid passageway 68. Third and fourth seal members 72 b, 74 b encirclethe outside of the second generally cylindrical portion 60 on opposingsides of the second fluid passageway 78. The second and third sealmembers 64 b, 72 b are separated by a middle distance that mayoptionally be placed in fluid communication with a vent passage 105. Thevent volume between the end 86 and first seal member 62 b may optionallybe placed in fluid communication with vent passage 140. The distal endof the filter cartridge 55″ may have an axial face 402 generallyparallel to the filter cartridge longitudinal axis 14 and offset to oneside of that filter cartridge longitudinal axis. Advantageously, theclosed end 86 of the lateral filter cap is adjacent a generallycylindrical plane conforming to a periphery of the housing 57 enclosingthe filter 59. The offset allows the end of the lateral filter cap 56′to not extend so far away from the sidewall of the housing 57 and thathelps reduce potential damage to the lateral filter cap 56′.

The above description is given by way of example, and not limitation.Given the above disclosure, one skilled in the art could devisevariations that are within the scope and spirit of the inventiondisclosed herein, including various locations of the fluid passagewaysand vent passageways through one or more portions of the manifold,barrel valve or filter cap. Further, while the above embodiments arebelieved to provide particular advantages for water filters of the typeused in residential and commercial appliances, the present invention isnot limited to water filters and may be used with filters for otherliquids and gases. Moreover, the various features of the embodimentsdisclosed herein can be used alone, or in varying combinations with eachother and are not intended to be limited to the specific combinationdescribed herein. Thus, the scope of the claims is not to be limited bythe illustrated embodiments.

What is claimed is:
 1. A filter cartridge for use with a filter apparatus manifold head having a flow inlet and a flow outlet, the filter cartridge having a filter element located in a housing with the filter element in fluid communication with a filter inlet and filter outlet so that liquid from the manifold flow inlet passes through the filter inlet and filter and out the manifold flow outlet, the filter cartridge comprising: a filter cap having a first generally cylindrical portion with a first fluid passageway extending radially inward toward a longitudinal axis of the filter cartridge and forming one of the inlet or outlet of the filter cartridge, the filter cap having a second generally cylindrical portion with a second fluid passageway extending radially inward toward the longitudinal axis and forming the other of the inlet or outlet of the filter cartridge, the filter cap having a closed top at one end with the first generally cylindrical portion closer to the closed top than the second generally cylindrical portion, the first and second generally cylindrical portions having respective first and second outer diameters with the first outer diameter being smaller than the second outer diameter, the filter cap having a first internal cavity formed in part by first generally cylindrical inner walls in fluid communication with the first fluid passageway and extending along the longitudinal axis, the filter cap having a second internal cavity in fluid communication with the second fluid passageway and formed in part by second generally cylindrical inner walls extending along the longitudinal axis; first and second seal members encircling the first generally cylindrical portion on opposing top and bottom sides of the first fluid passageway, respectively; third and fourth seal members encircling the second generally cylindrical portion on opposing top and bottom sides of the second fluid passageway, respectively, the second and third seal members being separated by a middle distance, a mounting flange connected to the filter cartridge and having outwardly extending mounting tabs configured to releasably connect the filter cartridge to one of an adapter or manifold head.
 2. The filter cartridge of claim 1, wherein the first inner generally cylindrical walls are smaller in diameter than the second generally cylindrical inner walls.
 3. The filter cartridge of claim 1, wherein a first channel is formed in the first generally cylindrical portion, the first channel encircling at least a substantial portion of the first generally cylindrical portion and located between the first and second seals and in fluid communication with the first fluid passageway.
 4. The filter cartridge of claim 3, wherein a first channel is formed in the first generally cylindrical portion, the first channel encircling at least a substantial portion of the first generally cylindrical portion and located between the first and second seals and in fluid communication with the first fluid passageway and an outwardly extending connecting flange at an opposing end of the filter cap; a second channel formed in the second generally cylindrical portion, the second channel encircling at least a substantial portion of the second generally cylindrical portion and located between the first and second seals and in fluid communication with the second fluid passageway.
 5. The filter cartridge of claim 1, wherein the mounting tabs have a thickness of less about ⅛ inch to about ¼ inch and are made of plastic.
 6. A method of testing water filter cartridges having a filter cap, comprising the steps of: pressurizing a void volume between an inlet and outlet of a water filter cap with a test gas, the void volume being located between two adjacent and coaxial seal members at least one of which defines a portion of a first flow path through the filter cap of a water filter cartridge, each of the seal members encircling a longitudinal axis of the filter cap, and providing a liquid tight seal between a portion of the filter cap and a wall abutting the two seal members to create the void volume; and checking to see if the test gas leaks past the two adjacent and coaxial seal members.
 7. The method of claim 6, wherein the checking step comprises monitoring the pressure of the void volume.
 8. The method of claim 6, wherein the checking step comprises monitoring the seals defining the void volume for leaks into the first flow path.
 9. The method of claim 6, wherein the checking step comprises monitoring the first flow path for the presence of the test gas.
 10. The method of claim 6, wherein each of the at least two seals define a portion of a first and second flow path through the filter cartridge.
 11. The method of claim 6, wherein the two seal members forming the void volume have different diameters.
 12. The method of claim 6, wherein the two adjacent and coaxial seal members comprise second and third seal members and the filter cap further comprises first and fourth seal members with the first seal member located axially above and coaxial with the second seal member and with the fourth seal member located axially below and coaxial with the third seal member, the first and second seal members each encircling a portion of a filter cap adjacent a top of that filter cap and further encircling opposing sides of a first water flow path of the filter, the third and fourth seal members each encircling opposing sides of a second water flow path of the filter, first seal member forming a top filter cap void volume bounded on a lower end by the first sealing member which seals against the wall which defines a cavity above the first seal member and into which cavity a top of the filter cap extends during testing, the second and third seal members forming a middle filter cap void volume between the filter cap and the wall, the fourth seal member forming a portion of a bottom filter cap void volume located between the bottom of the filter cap and a portion of the wall, at least one of the void volumes having a vent passage in fluid communication with the at least one void volume and a location outside the filter cap, the method further comprising: pressurizing at least one of the void volumes through the vent passage with a test gas and checking to see if the test gas leaks past the two seal members defining the at least one void volume being pressurized.
 13. The method of claim 12, wherein the checking step comprises monitoring the pressure of the void volume being pressurized, and wherein the pressure is a positive pressure.
 14. The method of claim 12, wherein the checking step comprises monitoring the flow rate of the test gas provided to the void volume being pressurized.
 15. The method of claim 12, wherein the step of pressurizing at least one of the void volumes takes about 5 seconds or less.
 16. The method of claim 12, further comprising pressurizing a plurality of the void volumes with the test gas and checking to see if the test gas leaks past the two seal members defining the plurality of void volumes being pressurized.
 17. The method of claim 16, wherein the checking step comprises monitoring the pressure of the void volume being pressurized, and wherein the monitored pressure is negative.
 18. The method of claim 16, wherein the first and second seal members have a first diameter and the third and fourth seal members have a second diameter, with the first diameter being smaller than the second diameter, and wherein the checking step comprises monitoring the pressure of the void volume being pressurized, and wherein the monitored pressure is positive.
 19. The method of claim 16, further comprising a fifth seal encircling the filter cap and coaxial with the fourth seal and located below the fourth seal to form the bottom filter cap void volume defined in part by the volume between the fourth and fifth seals and the wall between the fourth and fifth seals, with a lower vent path in fluid communication with the lower void volume, the method further pressurizing at lower vent path and lower void volume with a test gas and monitoring at least one of the flow or pressure of the test gas in the lower void volume.
 20. An assembly including at least a manifold and barrel valve for a water filter cartridge for an appliance, the assembly having a longitudinal axis, the assembly comprising: a manifold comprising: a manifold head having a manifold wall defining a first generally cylindrical manifold inner surface centered on the longitudinal axis with a first manifold fluid passage passing through the manifold wall and opening onto the first manifold inner surface, the manifold head having a second generally cylindrical manifold inner surface centered on the longitudinal axis with a second manifold fluid passage through the manifold wall and opening onto the second manifold inner surface, the second manifold fluid passage spaced apart a distance along the longitudinal axis from the first fluid passage and below the first fluid passage; a middle manifold vent passage extending through the manifold wall and opening onto one of the first or second manifold inner surfaces; a barrel valve having a barrel valve wall, comprising: a first barrel valve wall portion having a first outer, generally cylindrical barrel valve surface sized to fit inside the first manifold inner surface and a second barrel valve wall portion having a second outer, generally cylindrical barrel valve surface sized to fit inside the second manifold inner surface, the first barrel valve wall portion having a first barrel valve fluid passage extending therethrough, the second barrel valve wall portion having a second barrel valve fluid passage extending therethrough and spaced apart a distance along the longitudinal axis below the first barrel valve fluid passage, the first and second barrel valve fluid passages having a first position in which the first and second barrel valve fluid passages do not overlap and are not in fluid communication with any portion of the first and second manifold fluid passages and having a second position rotated about the longitudinal axis in which the first and second barrel valve fluid passages are in fluid communication with the first and second manifold fluid passages, respectively, the barrel valve further having a middle barrel valve vent passage extending through the barrel valve wall between the first and second barrel valve fluid passages, respectively, the middle barrel valve vent passage having a first position that does not overlap with the middle manifold vent passage and having a second position that is in fluid communication with the middle manifold vent passage; a top barrel valve seal encircling the barrel valve and longitudinal axis and interposed between the first manifold inner surface and the first barrel valve outer surface and located above the first manifold fluid passage and above the first barrel valve fluid passage; a first, middle barrel valve seal encircling the barrel valve and longitudinal axis and interposed between the first manifold inner surface and the first barrel valve outer surface and located below the first manifold fluid passage and below the first barrel valve fluid passage; a second, first middle barrel valve seal encircling the barrel valve and longitudinal axis and interposed between the second manifold inner surface and the second barrel valve outer surface and located below the first middle barrel valve seal and above the second manifold fluid passage and above the second barrel valve fluid passage, the first and second middle barrel valve seals defining a middle barrel valve void volume between those first and second middle barrel valve seals and the facing surfaces of the barrel valve and manifold abutting those first and second middle barrel valve seals, the middle barrel valve vent passage opening onto the middle barrel valve void volume when the barrel valve is in at least the second position; a first lower barrel valve seal encircling the barrel valve and longitudinal axis and interposed between the second manifold inner surface and the second barrel valve outer surface and located below the second manifold fluid passage and below the first barrel valve fluid passage; a top fluid passage seal interposed between the first manifold inner surface and the first barrel valve outer surface and encircling the first barrel valve fluid passage when the barrel valve is in at least the second position; and a bottom fluid passage seal interposed between the first manifold inner surface and the first barrel valve outer surface and encircling the second barrel valve fluid passage when the barrel valve is in at least the second position.
 21. An assembly as defined in claim 20, wherein the diameter of the first manifold inner surface is smaller than the diameter of the second manifold inner surface and the diameter of the first barrel valve outer portion is smaller than the diameter of the second barrel valve outer portion.
 22. An assembly as defined in claim 20, wherein the top and bottom fluid passage seals encircle the first barrel valve fluid passage and second barrel valve fluid passage, respectively, when the barrel valve is in the first position.
 23. An assembly as defined in claim 21, wherein the top and bottom fluid passage seals encircle the first barrel valve fluid passage and second barrel valve fluid passage, respectively, when the barrel valve is in the first position.
 24. An assembly as defined in claim 21, further comprising a middle vent fluid passage seal interposed between the one of the first and second manifold inner surfaces and one of the first and second barrel valve outer surfaces and encircling the middle barrel valve vent passage when the barrel valve is in at least the second position.
 25. An assembly as defined in claim 20, further comprising a middle vent fluid passage seal interposed between the one of the first and second manifold inner surfaces and one of the first and second barrel valve outer surfaces and encircling the middle barrel valve vent passage when the barrel valve is in at least the second position.
 26. An assembly as defined in claim 20, wherein the first manifold fluid passage and the first barrel valve fluid passage are in a first plane orthogonal to the longitudinal axis and the second manifold fluid passage and the second barrel valve fluid passage are in a second plane orthogonal to the longitudinal axis.
 27. An assembly as defined in claim 20, wherein and the middle manifold vent passage and middle barrel valve vent passage are aligned along a radial axis when the barrel valve is in the second position.
 28. An assembly as defined in claim 20, further comprising a manifold base with a filter opening sized to receive a filter cap of the filter cartridge, the manifold base having a lip extending around the filter opening on an upper surface of the manifold base with at least one tab opening extending outward from the filter opening, the barrel valve located between the manifold base and the manifold head which are configured to constrain the barrel valve to only rotate about the longitudinal axis during use of the barrel valve.
 29. An assembly as defined in claim 20, wherein the top barrel valve seal forms a top barrel valve void volume between the adjacent portions of a top of the barrel valve and the inner surface of the manifold that are enclosed by the top barrel valve seal, and further comprising a top manifold vent passage extending through the wall of the manifold and in fluid communication with the top barrel valve void volume.
 30. An assembly as defined in claim 28, further comprising a second lower barrel valve seal encircling the second portion of the barrel valve and longitudinal axis and interposed between the second manifold inner surface and the second barrel valve outer surface and located below the first lower barrel valve seal, the first and second lower barrel valve seals defining a lower barrel valve void volume located between those seals and the facing surfaces of the barrel valve and manifold abutting those first and second lower barrel valve seals; and further comprising: a bottom manifold vent passage through the second manifold portion and in fluid communication with the lower barrel valve void volume.
 31. An assembly as defined in claim 30, further comprising a bottom barrel valve vent passage extending through the second portion of the barrel valve and in fluid communication with the lower barrel valve void volume.
 32. An assembly as defined in claim 20, wherein the first barrel valve portion has a generally cylindrical, first barrel valve inner surface and wherein the second barrel valve portion has a generally cylindrical, second barrel valve inner surface coaxial with the first barrel valve inner surface and the longitudinal axis, the assembly further comprising: a water filter cartridge having a filter cap located along the longitudinal axis, the filter cartridge having a water filter therein, the filter cap comprising: a first filter cap portion having a first filter cap fluid passage extending therethrough to a first, generally cylindrical, filter cap cavity, the first filter cap portion configured to fit inside the first barrel valve inner surface and be in fluid communication with the first barrel valve fluid passage during use; a second filter cap portion having a second filter cap fluid passage extending therethrough to a second, generally cylindrical, filter cap cavity, the second filter cap portion located below the first filter cap portion and configured to fit inside the second barrel valve inner surface and be in fluid communication with the second barrel valve fluid passage during use; a first, middle filter cap seal encircling the first portion of the filter cap and longitudinal axis and interposed between the first portion of the filter cap and the first barrel valve inner surface and located above the first filter cap fluid passage; a second, middle filter cap seal encircling the filter cap and longitudinal axis and interposed between the filter cap and one of the first or second barrel valve inner surfaces, the second middle filter cap seal located below the first, middle filter cap seal and above the second filter cap fluid passage, the first and second middle filter cap seals defining a middle filter cap void volume between those seals and the facing surfaces of the filter cap and barrel valve abutting those first and second, middle filter cap seals, the middle filter cap void volume being in fluid communication with the middle barrel valve vent passage and the manifold middle vent passage when the barrel valve is in the second position; and a first, lower filter cap seal encircling the second portion of the filter cap and the longitudinal axis and located below the filter cap second fluid passage.
 33. The assembly of claim 32, further comprising a top filter cap seal encircling the first portion of the filter cap and located above the top filter cap fluid passage; and a bottom filter cap seal encircling the second portion of the filter cap and located below the second filter cap fluid passage.
 34. The assembly of claim 32, wherein the top filter cap seal forms a top filter cap void volume defined by the top filter cap seal and the facing surfaces of the filter cap and barrel valve abutting the top filter cap seal, and further comprising a barrel valve top vent passage extending through the top portion of the barrel valve and in fluid communication with the top filter cap void volume; and wherein the top barrel valve seal forms a top barrel valve void volume between the adjacent portions of a top of the barrel valve and the inner surface of the manifold that are enclosed by the top barrel valve seal, the top barrel valve void volume being in fluid communication with the barrel valve top vent passage, and a top manifold vent passage extending through the wall of the manifold and in fluid communication with the top barrel valve void volume.
 35. The assembly as defined in claim 32, further comprising: a second, lower filter cap seal encircling the second portion of the filter cap and the longitudinal axis and located below the first, lower filter cap seal and defining a lower filter cap void volume between the first and second lower filter cap seals and the facing surfaces of the filter cap barrel valve which abut the first and second lower filter cap seals; a second lower barrel valve seal encircling the second portion of the barrel valve and longitudinal axis and interposed between the second manifold inner surface and the second barrel valve outer portion and located below the first lower barrel valve seal, the first and second lower barrel valve seals defining a lower barrel valve void volume located between those seals and the surfaces of the barrel valve and manifold abutting those first and second lower barrel valve seals; a bottom manifold vent passage extending through the second manifold portion and in fluid communication with the lower barrel valve void volume; and a lower, barrel valve vent passage extending through the second barrel valve portion and in fluid communication with the lower filter cap void volume and the lower barrel void volume when the barrel valve is in the second position.
 36. The assembly of claim 35, wherein the bottom manifold vent passage and barrel valve vent passage are radially aligned when the barrel valve is in the second position.
 37. The assembly of claim 32, wherein the first manifold inner surface has a diameter smaller than the second manifold inner surface and wherein the first portion of the barrel valve has a first inner diameter that is smaller than an inner diameter of the second portion of the barrel valve, and wherein the first filter cap portion has a diameter that is smaller than a diameter of the second filter cap portion.
 38. A lateral filter cartridge for lateral connection with a filter manifold head having a flow inlet and a flow outlet, the filter cartridge having a longitudinal cartridge axis and a filter element located in a filter housing with the filter element in fluid communication with a filter inlet and filter outlet so that liquid from the manifold flow inlet passes through the filter inlet and filter and out the manifold outlet, the lateral filter cartridge comprising: a lateral filter cap having a first generally cylindrical portion with a first fluid passageway extending inward toward a longitudinal axis of the lateral filter cap, the lateral filter cap axis being in a plane orthogonal to the filter cartridge axis, the first fluid passageway forming one of the inlet or outlet of the filter cartridge, the lateral filter cap having a second generally cylindrical portion with a second fluid passageway extending inward toward the lateral filter cap axis and forming the other of the inlet or outlet of the lateral filter cartridge, the lateral filter cap having a closed end with the first generally cylindrical portion further from the filter axis than the second generally cylindrical portion, the first and second generally cylindrical portions having respective first and second outer diameters with the first outer diameter being smaller than the second outer diameter, the filter cap having a first internal cavity formed in part by the first generally cylindrical portion and in fluid communication with the first fluid passageway and extending along the lateral filter cap longitudinal axis along a length of the first and second generally cylindrical portions of the lateral filter cap, the filter cap having a second internal cavity extending along the second, generally cylindrical portion of the lateral filter cap and comprising an annular recess encircling the first internal cavity and extending along the filter cap longitudinal axis, the lateral filter cap connecting to a distal end of the filter housing enclosing the filter; first and second seal members encircling the outside of the first generally cylindrical portion on opposing sides of the first fluid passageway, respectively; and third and fourth seal members encircling the outside of the second generally cylindrical portion on opposing sides of the second fluid passageway, respectively, the second and third seal members being separated by a middle distance.
 39. The lateral filter cartridge of claim 40, wherein the distal end of the filter cartridge has an axial face generally parallel to the filter cartridge longitudinal axis and offset to one side of the filter cartridge longitudinal axis, with the closed end of the lateral filter cap adjacent a generally cylindrical plane conforming to a periphery of the housing enclosing the filter.
 40. The lateral filter cartridge of claim 38, further comprising a portion of a locking mechanism on the lateral filter cap to retain lateral movement of the filter cap along the lateral filter cap axis.
 41. The lateral filter cartridge of claim 38, wherein the filter cartridge has a distal end with an offset tubular neck located on one end of the filter in fluid communication with the first internal cavity of the lateral filter cap, the neck being offset to one side of the longitudinal filter axis to locate the closed end of the first portion toward the filter cartridge longitudinal axis. 